The most blatant example is Germany and Italy. They've seen each other naked often, share a bed, and in one strip, Italy bursts into Germany's shower to ask him if he "likes" him and demands that Germany tell him he loves him. When Germany does, he shouts, "Yahoo! I love you too!" Then their friend Japan catches them both naked in the shower. Italy's reaction? "I did it, Japan! I got closer to Germany!" Not to mention the hints that Germany is Italy's long-lost childhood love. It's so blatant that it eventually crosses the line from subtext to text.
Germany: Hey Austria, what type of relationship do you call it when you see them every day, and they hug and kiss you, and go in the bath with you, and sleep in the same bed with you (while they're naked)..?
Austria: DON'T SAY SUCH VULGAR THINGS! ...Oh, you meant HIM.
In Buon San Valentino, Germany gets confused on Italy's behavior and decides to buy a manual that gives information about couples. After Italy comes to him and gives him flowers, he becomes convinced that Italy has a crush on him - especially when Italy confesses his first love was a boy- and decides he actually wants to be with Italy. He asks Italy on a date and proposes to him, but everything turns into a disaster. In the end, as Germany stares petrified at Italy, he remembers Chibitalia and it seems the memories are from HRE's point of view, which is a clear hint that Germany is the Holy Roman Empire, while a scared Italy repeatedly asks him what's wrong.
And Germany asks Italy on a date and wears his best suit. He also ends up getting miffed when he sees Italy flirting with girls. "I can't believe you! Flirting when you've got me!" Germany also gives Italy some flowers. Not to mention giving Italy a ring in the shape of a tomato and hugging him when "proposing" to him.
The flowers Germany gives Italy are stated as being heliotropes which signify eternal devotion.
Even though he's nervous when about to go on his date, he admits the last few weeks haven't been bad. "Is this what they call happiness?"
Also, in the same strip, there is a panel that shows a chibi Italy shouting "I love you, Germany ~ Hug me!", while Germany thinks about Italy and his strange tendencies of always hugging and kissing him.
There is another panel where Germany remembers a moment in which Italy - while wearing an apron- feeds Germany in a similar way housewives feed their husbands and they're both blushing.
In the 2010 Christmas Special, Germany asks Italy to strip and he does it without question. Even though Romano protests that it must be for some peverted reason, Italy says "Even if that's true, it doesn't bother me at all!" Germany then inspects Italy's chest and butt, both of them blushing heavily the entire time. It Makes Sense in Context, but still.
Next up is England, who's been Ship Teased with no less than three other characters:
There's that strip and episode in which France asks England to marry him. Even if it was only for economic reasons and England wanted nothing to do with it, it doesn't change the fact that France asked England to marry him and tried to drag him off... somewhere to persuade him after failed attempts to force him to sign the contract. It's made even worse/better if you view their Sitcom Archnemesis dynamic as Foe Yay and consider that they always seem to spend their Christmases getting drunk together.
In the April Fools 2011 event England is complaining about the nurse dress, France says something like "That's our relationship"
In the dub of Paint it, White!, there's a part where France and England are paired up to search the alien ship they're on. While going through the aliens' records, they find out that the aliens believe that England and France "love each other. Sexually". Later in the movie, after the nations are forced to abandon ship and wash up on an island, France and England walk out of the woods on the island together.
Then there's that strip about the Anglo-Japanese alliance that seems tailored to tease at England/Japan. It's made even more obvious in the anime (specifically, episode 30), where England takes off his clothes in front of Japan before he goes to the hot springs (and Japan doesn't even blink, unlike in the Please Put Some Clothes On moment of episode 15), and later shows up wearing only a towel, but not bothered with Japan's presence despite his partial nudity. The anime producers also seem to like randomly putting England and Japan together in several anime fanart and covers, much to the delight of many England/Japan fans.
In a web comic which was about Harry Potter spoilers England is also shown stripping in front of Japan when Japan freaked out because he was wearing a T-shirt with Harry Potter spoilers stating that he was doing it for his own sake, not for Japan's although he had the spoilers written in his skin.
In Episode 22 England and Japan have a heartwarming moment that goes like this:
Japan: "I want to form an alliance with YOU at all costs, Mr. England."
England: "What...? Japan...Is that true? I-I see...I want that too."
Japan: "*breathlessly* Mr. England..."
Then zooming in on their soft, sweet smiles, wind blowing through their hair
And then England switches over into classic "tsundere mode"...
The Drama CD adaptation cranked up the Ship Tease of the aforementioned "stranded together on an island" strip by turning it into an Everyone Can See It scene with France even saying that the other nations can't sleep because of their "lovers' spat", to which England replies, "Don't call it a lovers' spat!" Even the dubbers seem to have caught on, as France in one episode of the dub tells America and England to "finish releasing sexual tensions".
It has been noted by many a shipper that neither America nor England deny the "sexual tensions" line. In fact, England says "That's weird, France has a rational point!" (Which is more likely directed to France's other statement about how they have to get back to their meeting, but still...)
In the Hetalia Movie When America is hit by the Picts magic, England stops attacking and shouts America's name before getting hit as well.
The Hetalia 2011 Fool's Bath comics has even more. Apparently, there's someone later revealed to be Spain out there that is blackmailing the nations to wearing embarrassing clothes (AKA crossdressing). America explains to England that he would rather wear a mini skirt (or a naked apron than the embarrassing picture that he was threatened with to be let out in the public. England doesn't make him feel any better and tells him he looks good in that outfit. (Mind you that America is half naked and England seems to be blushing when he says that.)
Expanding on the April Fool's Bath, England's embarrassing photo was him sleeping with a teddy bear. America has bear ears on his outfit.
And now in the PSP game Gauken Hetalia America gets himself in trouble almost drowning and England dives into the lake and saves him. Later that day, America thanks England and says that England will always be his hero. And America did it because he wanted to let England save him so he could be the hero for once.
Himaruya also drew a picture of the chibified Allies sleeping◊, and England sleeping on what is assumed to be America's folded up jacket. It has also been suggested to be his arm, but in comparison to Iceland's arm, it looks much different. The colouring is also different, and the arm would be very disproportional if outstretched. Not to mention that every character is in their full uniform except America, who is missing his jacket.
Hetaween 2011: America deliberately left out information about the contest he started so England would be the only one in a "normal outfit" compared to everyone else but left a note telling him to meet him alone. This is so America could have England dress them both up as a Batman theme of Batman (America) and Robin (England). In other words, even though America stated from the beginning that he was going to win the competition he wanted to win it with England by his side. Not to mention the fact that he made England dress in the skin-tight short-shorts version of the Robin outfit. And England is completly embarassed by this, like he was in the April Fool's strips with the short nurse dress, but he dressed in it anyway without being blackmailed.
According to the Hetaween event, England was also America's first follower on twitter.
In the Birz comic, an officer commented on how they were siblings. England starts blushing heavily, saying things like, "It's not like that at all! I mean- how do you put it—" Where as America simply sips his soda and says, "You. What are you saying?", Proving that neither of them consider each other as siblings. (Not to mention England struggling to define their relationship...
There are two comics given to the fandom in the Hetalia 2011 Bloodbath. The first one is a severe Mood Whiplash of the American Revolution as during the war, England constantly wrote letters to America asking him to stop this nonsense and come back and America almost given into the temptation if not for George Washington. (This could be seen as more family bond then romantic one). Then England goes back thinking about how America never use to throw things away before giving him chocolate (a Call Back from the Valentine's comic where America demanded chocolate) and walking away with America as confused as ever.
And then there's Japan and the bits (and a bucketload, in at least one case) of Ship Tease he gets with several other characters:
America and Japan don't receive any real indicators that they're anything more than good friends in the modern day strips, but upon reading the author's notes about the gender-flipped counterparts of the countries and finding that he considers fem!Japan to have "a complicated yearning for America," one can't help but wonder if that might also be true for male!Japan, what with his tendency to always side with America and him inviting America to his place to see the first Cherry Blossoms...
More than one fan couldn't help but see a sort-of love triangle in the strips featuring Netherlands and isolationist!Japan, what with Netherlands coming to visit the hikikomori nation with tulips and warning him about how America "is young so he might try to force his way in". And then Netherlands becomes anxious when he learns that America succeeded in getting Japan to open up... yeah, you can't really blame these fans. Especially if you know what tulips mean in floriography. (Not to mention that their pets seem to get along rather well.)
In the published manga, Italy declares Japan to be cute when they meet for the first time, and there's a strip on the Volume 3 back cover about Italy trying his best to get Japan to smile (though he fails hilariously). Not to mention that early webcomic strip where Japan demanded that Italy "take responsibility" for hugging and kissing him on the cheek; of course, nothing ultimately came out of it, but still...
In Hetaween 2011 Italy cuddles with/hugs Japan close. And Japan says Italy's costume is cute.
Last but definitely not least, there's Greece who's shown to have a lot in common with Japan and is stated in the author's notes for their first strip together to like Japan. As to what kind of "like" that is...well, Greece's interactions with Japan include him learning how to speak Japanese, taking all of Japan's snacks after the other nations dismiss them, not wanting Japan to see him with messy hair (while they're under an Umbrella of Togetherness, no less) and getting upset by Japan's well-meaning but awkward-sounding reassurances until he begins wondering if Japan might actually be trying to do this with him. Oh, and he almost certainly had sex with Japan at least once (even if Japan denies it), and his new profile states that Japan is "right here". Take from that what you will.
Volume 2 of the manga has a chapter entirely focused on their relations that gives us moments like Japan giving a suspiciously evasive response when Greece asks him if he's the "friend" Japan's referring to, Greece asking Japan if he wants to try a naked check-up that the ancient Spartans used to do, and Turkey (who's stated to like Japan too in the author's notes) demanding to know if Greece is planning to "invade" Japan that sparks off a quarrel between the two of them about which one of them Japan spends more time with... yeah, they're not even trying to hide the subtext there.
One sketch shows Greece wearing a chiton and cat ears and holding up a piece of cloth for a visibly flustered/embarrassed Japan to see, which indicates that he either wants Japan to wear a chiton too or is flashing his unmentionables at him.
Germany/Italy and Austria/Hungary are Official Couples, of course, but there's actually some teasing at Germany/Austria in one pre-WWII strip where Austria willingly concedes his sovereignty to Germany without a fight despite Hungary and Italy's objections, and is later shown to either live with Germany or be his neighbor. Plus, in one anime episode, he acts like a nagging housewife towards Germany, complaining about his dirty underwear.
Not to mention that in the Valentine's Day strip, Germany wants to 'practice' with Austria, since he doesn't know what to do with a guy and Austria willingly takes his pants off. Of course, they end up arguing instead of going through with it and the whole thing arose out of Germany freaking out about Italy being a man, but still...
Spain is just affectionate toward the Italy brothers in general (though he seems to spend much more time with Romano, even after he's no longer Romano's boss), but Romano seems awfully Tsundere toward him, both as a kid when he got jealous whenever Spain paid more attention to his brother than him and as an adult when he frantically ran around trying to help Spain after the latter fell ill. There's also the fact that Spain used to tug Romano's hair curl, not knowing it was his erogenous zone, which seems to be a parallel to how Germany also sometimes pulls Italy's hair curl, unaware of how it really makes Italy feel.
Many Spain/Romano fans delight in pointing out that when Spain proposed to Romano, instead of bluntly turning him down or giving him a pummeling, Romano said "Minimum: Three meals and a nap with pasta every day." In other words, while Romano didn't exactly say yes, he certainly didn't say no either and may in fact have accepted it in a very roundabout way. Of course, Spain still took his response as a rejection, but that's Spain for you.
Spain's face here◊ while he imagine both Italies hugging him is absolutely obscene.
Sweden considers his partner Finland his wife and refers to him as such, much to Finland's horror. He also sews his best old clothes when he gives them to Finland as soon as he remarks on their height difference, blushes more than once in his presence, and even when Fin doesn't like to be called "Su's wife", they live together almost as if they were. There's also an adopted child (Sealand) and a family pet (Hamatamago) involved, encouraging a Has Two Daddies interpretation of the relationship. Take from all of that what you will.
The animators ramped up the Ho Yay quite a bit in the adaptation of "Runnin' away with Su". The mere beginning card was infamously shoujo-ish and sparkly, to start...
When the two were colonizing the Americas together (that alone being plenty of ship tease) Finland mentioned spotting a small boy in the area (a young America, in fact). Sweden's response is to wonder if he wants kids and say he'll "do his best"... meaning that he somehow intended to get him pregnant?
Het shippers also have their bits of Ship Tease! Many shippers see the infamous"weak point"scene to tease at the possibility of Prussia being Hungary's Unlucky Childhood Friend, especially considering that some of the dialogue there makes it sound like Prussia found Hungary's "weak spot" to feel kind of nice, and it's not helped by Prussia apparently being jealous of Hungary and her ex-husband Austria as they spend Valentine's Day together and breaking down into tears in the middle of his "I'm happy being alone! Really, I am!" rant at Christmas when he sees Austria and Hungary walking by together.
As mentioned above, Austria and Hungary are divorced but appear to still be in a romantic relationship, with Austria sending Hungary a present for Valentine's Day which she accepts very happily, and him willingly stripping when a disguised France tells him he has to do so to be able to get Hungary a hat she liked (and pretty much squeed over when he said that he'd buy it for her, saying that she'd "treasure it forever!").
Hetaween 2011: Hungary dresses as a Bifauxnen prince, and Austria gets into a dress (though he wears pants underneath), presumably as her "princess".
While we're talking about het, some fans view Russia's insistent attempts to get Ukraine to like him again to be something of a Ship Tease. The way France suggests that Russia do that doesn't make it any better.
For being in the official comics all of three times, Seychelles gets a surprising amount of Ship Tease with France. For instance, during the Christmas Bloodbath 2007, France tells Finland that his shinanigans were largely inspired by "his girl" leaving him◊. A picture◊ from later in the event quite effectively shows who "his girl" is.
Meanwhile, in Gakuen, he spends nearly every second he's around her trying to woo/grope her, and if that's any reflection on the canon...
Though it's just in Gakuen Hetalia, she also has some with England. When he's not bossing her around, he's having tea with her and inviting her out to dinner. Before he ruins them by being himself, Seychelles seems to find both of these things sweet and endearing.
Also the PSP version of Gakuen Hetalia; he took her to this place where couples go to see the stars but claims that it was an accident. Knowing England's Tsundere nature, he probably was lying. He also gave her a necklace at that scene.
And in th Hetalia Bloodbath 2011, she gets some with Cuba. Seychelles is reacting very badly to the snow and cold (which is rather understandable considering her climate), and pretty much passes out in a really worried Cuba's arms. Later we see the girls's reunion, and it looks like Seychelles managed to drag Cuba with her there...
Russia's fondness for Lithuania is pretty much canon, but the strip where Lithuania falls asleep on Russia's couch and wakes up to Russia who for once is in a mostly-sane mood is the biggest Ship Tease for them and shows that Russia is capable of kindness toward Lithuania. Unless it was only a dream Lithuania was having, but that would then mean that Lithuania was dreaming about Russia being kind to him, which is even more of a teasing interpretation.
In the Bloody Sunday strip, Russia and Lithuania share a personal moment when Russia tears up over how he can't seem to make his people happy. Instead of fear, Lithuania looks at Russia with concern and he looks back at Lithuania with a tearful smile.
In one of the Drama CD Adaptations, Russia says how much he loves Lithuania's cooking and even winks at him.
In the strip Russia's Big and Little Sisters Belarus wonders whether Russia "likes that jerk that much", which theories speculated it to be Lithuania who is known to be the favorite of Russia.
Lithuania is once shown wearing a maid costume with Russia lashing him with a whip in the While You Were Gone strip.
The Russia/China pairing doesn't get much tease in the webcomic (aside from Russia stalking China a couple of times in a panda suit...okay, that very well could be seen as Ship Tease given Russia's nature), but episode 38 of the anime has Russia insisting that China has to be the G8 member missing from their meeting (note that China is definitely not part of the G8) and England snaps back, "No, you just want him to be here!" Cue Squee from Russia/China fans.
The one notable instance of tease for this pairing in the webcomic follows the strip concerning China's history with Japan. In this strip, Russia and China are in a bar with China drowning his sorrows over his bad relationship with Japan and Russia being surprisingly sweet and supportive... until he makes his infamous comment about all becoming one with Russia. Still, up until that point, it's a rather touching moment for the pair, and more than enough to make the fans go "D'awwwwwww..."
Another moment between the two of them comes when many other nations are making numerous territorial demands of China after the Boxer Rebellion, and Russia butts in to tell them off for taking advantage of China in such a weak state and that he should be given time to recuperate. Of course, this moment is similarly punctured when Russia goes on to declare that China obviously wants to live with him instead, elicting a Big "NO!" from China, but it's still another unexpectedly sweet moment for Russia up to that point.
Of course, theirseiyuu just had to make Ro/Chu fans squeal by getting along really well to the point of standing out as the two most immature people present during the first live seiyuu event. Pandaryoshka, anyone?
On the Christmas 2011 strip, we have China and India fighting for who is Russia's best friend! By the way Russia, you haven't answered...
It turns out that this is something Lithuania was dreaming of...cue the Russia/Lithuania fangirling.
The July Birz issue has China acting very concerned about Russia having a cold, fussing over him and touching him a whole lot ("Your muscles are stiff and the flow of your qi is not good at all!"). Russia doesn't seem to mind this at all, playfully winking at China.
China has an obvious affection for Japan, one that some fans see as more than familial. In the Asian and Western festivals comic, China invites Japan over to help make a New Year's feast. Japan obediently goes, but soon wants to leave thanks to China's very Asian parent-like remarks about his posture, etc. Japan tells China that he wants to give him a gift. China blushes bright red, says he wants the gift because it's from Japan, and swoons on his feet. Japan sticks a paper that says "This person is bugyou (i.e. magistrate)" on China's back, calling him out for his nitpickyness, and decides to spend the rest of New Year's with Italy and Germany. There's also China Drowning His Sorrows at a bar during WWII about his bad relationship with Japan, which is strikingly similar to England's tendency to rant about America while drunk.
China's second character song, "Aiyaa Yonsennen", is...pretty much about Japan. ("Even if our countries are different, if our worlds are different, if our characters are different, I always want to...gaze at the same moon as you." *sniff*)
The skit that came with the character single, "Asian and Western Festivals" has even more shiptease. He is ambivalent towards Christmas because it is a Western holiday, but when he receives an advent calendar from Japan, he is very pleased because of who the gift-giver is, and says "Of course I donít mind! Since Japan gave it to me, Iíll treasure it forever!" Forever!
China has a sheep-counting CD with him too, courtesy of Honeybee. Mind you, this entire series is about characters trying to go to sleep together by counting sheep. Sleepytime. Bed. Granted, the pairings in the CD series tend to group family members or geographically close nations together, but still...
The sheep-counting CDs? China and Japan's stood out for one particular piece of dialogue...
Japan: As China pulls at his hand..."China, where are you going?"
China: "A bedroom! If you're going to act this way, then I'll...just have to...get you too relax today!"
Japan: "Please wait China! Please let go of my hand.I-I have to..."
China: "Just follow me, and no complaining now!"
Japan then makes suspicious moaning/panting sounds...
And even in context, this has caused plenty of raised eyebrows...
And then there's Korea's overt fawning over his beloved "aniki" China (and Japan, to a much lesser extent). It's just as blatantly one-sided as China's possible feelings for Japan, but you do have to wonder if the author is trying to make a point about China's apparent indifference toward Korea's affections when he seems set on giving China many strips with Korea alone where China seems fine with Korea, even agreeing to make a movie and spending Christmas together with him, until Korea goes overboard with his Korea-ness (yanking down China's pants to show his white underwear (and panda birthmark), anyone?). Plus, China actually gets mad at Korea once when Korea falls asleep while he's out buying dinner for them... that sound just a little bit Tsundere to you?
Korea: To both China and Japan..."Your breasts are mine, da ze!"
Poland/Lithuania, anyone? And I quote, "Even if you, like, hate me... It totally doesn't change that I like you!" (It must be noted that the "I like you" part of the quote can translated to love instead of like... take that as you will.) Not to mention Poland waiting for (naked) Liet in a very... provocative outfit in one of the Christmas strips!
Their Marukaite Chikyuus add even more tease. The last three verses of both of their songs are about each other, and what they say made many shippers incredibly happy. "Fooling around" indeed.
Volume three of the manga has quite a bit more of their common story... including the creation of the Polish-Lithuanian alliance through the marriage of their bosses (Grand Duke Wladislaw II, for Lithuania; Queen Jadwiga, for Poland). And to quote Poland on that: "Like, Show me your penis and junk!" One can only wonder if Liet did end up showing him or not.
The anime adaption of that strip makes it even more blatant - It focuses more on Lithuania and Poland meeting for an arranged marriage than it does on Jadwiga and Wlaislaw.
Prussia's April Fools blog and drama CD contain some teasing for Prussia/Italy, with a bit of Germany/Italy thrown in for good measure.
The blog also shows some hints of Prussia/Austria, judging by Austria's comment when he thought Prussia had died from eating England's food. There's also the part where Prussia went to Austria's house to tease him, and Austria pretty much lets him, with a blush on his face, until Hungary comes and gives Prussia some frying pan love. In the drama cd, Austria sounds concerned when Prussia fainted, and even asks if he's alright.
In the Christmas 2010 special, Prussia and Austria end up sleeping next to each other with their clothes all torn up after being delivered home safe and sound.
Cuba and Canada. Even though Cuba does frequently mistake Canada for his despised brother America, he does his best to apologize for it with a present of ice cream and invites him to see his country too. They also get a lot of interaction during Hetalia Bloodbath 2010, even finding time to dancedo yoga together in the midst of nations being kidnapped, and Canada is the first person Cuba calls when he hears about the disappearances.
And don't forget The Movie whit both of them working together and Cuba hugging Canada with a big smile on his face.
There's also some teasing for America/Lithuania. First there are the Outsourcing Strips, including the one where America and Lithuania sleep in the same bed (even if that one's also a tease for England/America and Poland/Lithuania), and there's a bonus strip for Christmas that has America complimenting Lithuania on his stripping skills and then carrying him bridal style to Poland's house.
Switzerland and Liechtenstein's relationship can be seen as a very close sibling relationship or closeted Brother-Sister Incest. Liech pretty clearly considers Swiss as her ideal man (cuts her long hair to look more like him, trains with him even when she's more of a pacifist, is incredibly devoted to him), and she's pretty much the only nation whom he seems to be close to in modern times (took her under his wing despite his own difficult situation, is incredibly protective of her, can't bring himself to reject the pink pajamas she gives him)...
Well, it's not like they're actual brother and sister anyway, since he found her on a deserted alley and instantly took her into his house. Plus, he constantly blushes around her, Liechtenstein also has the habit of getting too lovey-dovey with him, they often hold hands, despite them not being actual siblings and apparently not having a really big age difference, as it's noticed in Himaruya's drawings.
Switzerland is hinted to either be or have been in love with his Forgotten Childhood Friend Austria. A flashback of their childhood shows him blushing around him when giving him a piggyback ride after he got beat up by Hungary, yelling at Austria for yet again being weak and making him save him again. He also tends to act like a Tsundere around him. He also dreams about Austria, and blushes when asked how he slept.
Switzerland/Belgium had some Ship Teasetoo. Scroll down and you'll see Belgium trying to put cat ears on Swiss.
Switzerland had also once blushed intensely when Austria mentioned that he had a close relationship with Germany.
Spain also gets a bit of this with Belgium, who lived with him at around the same time as Romano. Complete with her big brother the Netherlands disapproving and wanting her to stay away from Spain. In the Hetalia Bloodbath 2010, when Spain's feline parallel universe self attacks her, Belgium just feels sorry for whoever that is wandering around in the cold and gives him her scarf. Later, he calls Parallel!France and tells him that he's fallen in love and doesn't want to go home, and is seen happily nuzzling the scarf.
For that matter, Spain and Netherlands. They are shown spending Christmas together, much to Netherlands' annoyance. And when Netherlands got attacked by a mysterious figure, Spain found the closest thing he could find for a weapon to protect them both.
In a recent blog post, Iceland and Seychelles are shown standing really close to each other. Seychelles is smiling and Iceland looks flustered.
In the Taiwan-centered strip of the fourth volume, Taiwan is lightly shipteased with two charas: Japan (whose fortune she tries to read without much result, but she still gets praise for being positive) and Vietnam (whose looks she praises when Vietnam says "I'm Not Pretty!")
Korea's insistence that she'd play his "heroine" during Hetaween 2011 could be seen as shiptease too. Granted, he wanted China to play the part earlier, but...
It also coincides with both of them being shipteased with China. When China's health seem to be failing, we have Korea being willing to aknowledge that many things were originated in China (and this isKorea we're talking of]] and Taiwan going Tsundere and making him a cure with Mochimerica's legs at its main ingredient.
And Taiwan's shipteased with Japan again, too. She picked her costume based on an internet idol made in Japan (Silverlight) and wanted him to see her on it real bad.
Possibly a stretch, but India and Prussia's dance scene (as well as their tweets to each other) during Hetaween 2011 pleased many fans. It doesn't hurt that India genuinely seems to like him and he and Prussia seemed pretty friendly with each other.
Austria tricking Germany into being his chair; one of the incidents that spawned Couchtalia.
The Spain/Romano strip; Romano has some work he has to do, and Spain offers to give him his "cheerfulness for a charm", while Romano says he "doesn't want it"... then Spain crawls under the desk, there's a pause... then Spain does something and Romano snaps "I told you not to!". Fans were not shy at all about the dirty implications of all this, especially before the strip was translated.
And for the girls (sorta), Liechtenstein thought that Kugelmugel was a girl and proceeded with much hugging and fangirling anyway.
Romania/Bulgaria too! They certainly seem to be rather close during the times they both "worked" for Russia, and taking the Real Life Bulgarian/Romanian friendship in account...
Hungary is also rather flirty with Ukraine when they have a strip together in the fourth volume, teasing her, calling her cute nicknames, and trying to convince her to wear a very revealing dress. Ukraine, meanwhile, actually seems to return the teasing a little bit.