Chris and Chef have an interesting relationship throughout the seasons. In "Zeke and Ye Shall Find", when Chris and the other contestants get captured by Feral Zeke, the only person Chef is worried — and we're talking deeply worried — for is Chris. Then there's "The Chefshank Redemption" in which Chris pretty much unsuccessfully tries to ask Chef out on a date with all the awkwardness that comes with it.
Chris: So, you've ever seen that prison flick? The one with the guy in it, you know, the guy with the face? (Chris refers to himself here. Chef doesn't bite) So, are you doing anything after work? We could always rent a... or not. I was busy... anyway. Very busy. ...Just throwing it out there.
There was that crack about "so we meet again" from Noah to Justin in the Island special, which seemed odd considering they'd never interacted before. This, combined with the fact that Justin and Noah are two contestants frequently thought to be gay by the fan base, inspired a lot of theories that the two had a thing at Playa Des Losers.
Noah and Cody:
In Episode The Big Sleep, Noah and Cody can be seen sleeping next to each other, Noah kissing Cody's ear in his sleep. Cody wakes up and looks at Noah, smiling.
In the Total Drama Action special, while the contestants wait for help, Noah can be seen sleeping near Cody.
Later, Noah and Cody can be seen sleeping together, Noah sleeping on Cody's lap (as pictured above).
The two are often seen near each other in TDI and TDWT.
Noah can be seen cheering Cody on in the episode Hawaiian Punch
Duncan seemed a little too happy about holding onto Noah's lip in the first episode. His only other interaction with Noah was pantsing him in the Island special. Not just pulling his pants down, but pulling them completely off, and then staring at them for a few seconds.
Owen: I'd like to top his honor roll!...D-Did that sound creepy?
Owen's pretty quick to hug Noah for warmth, after Noah's rejected by Bridgette in "Anything Yukon Do, I Can Do Better"
Owen: You can cuddle me, buddy!
While they are just friends, it should be noted that Owen seemed to be more distraught over the loss of Noah than the loss of Izzy, his (ex-)girlfriend. While Izzy may have gotten a whole song dedicated to her, Owen was worried about Noah up until he himself was eliminated!
In "African Lying Safari", when escaping quicksand Duncan hugs Alejandro around his shoulders and lays directly on top of him, not to mention they stay like that for quite a while and Duncan doesn't seem to mind the position.
In the episode "Hawaiian Style" Harold gushes about Cody.
"Cody's a deer. And not just for his big blue eyes and tiny tail."
"African Lying Safari" has Ezekiel lying on top of Duncan, both of them fast asleep from the tranquilizer gun.
The relationship between Lindsay and Beth. They went on vacation together to paris and were seen holding hands while jumping off a tower to get on a horse in "3:10 To Crazy Town".
Beth: I'll miss your fruity lip goop!
Heather behaved a lot like a stalker towards Courtney in "One Million Bucks B.C" as she spent a huge portion of the episode attempting to acquire a lock of Courtney's hair. She succeeds in doing this when she sneaks into the confessional while Courtney is inside.
In the episode "If You Can't Take The Heat", Heather orders Beth to switch places with Leshawna during the cooking challenge and while Beth tries to walk over to where Heather ordered her, Leshawna blocks Beth from walking and places her hand on Beth's chest.
Heather attaches another cable to Gwen's skirt during the rock climbing portion of the trust challenge and uses the cable to rip off Gwen's skirt completely to reveal her underwear while enjoying it.
Gwen and Courtney:
"Heroes Vs Villains" had Gwen giving flowers to Courtney (although Courtney was allergic to them)...to apologize for kissing Duncan, of course. Seriously, Gwen seems more interested in getting Courtney's forgiveness than her relationship with Duncan in All-Stars.
Gwen outright states that the only reason she decided to participate in All-Stars was to make up with Courtney, and she's devastated because she doesn't think it will happen. Courtney's defenses slip for a moment after she overheard this.
In "Suckers Punched", Gwen and Courtney have to fight each other in the challenge but refuse to do so due to their reigniting friendship. Chris then uses various clips of Duncan and Gwen kissing to anger Courtney enough so that she attacks Gwen. Gwen fights back and the two girls end up battered and bruised. Gwen eventually admits she only wanted to make things better with Courtney, and Courtney responds that she had gotten over Duncan and never truly missed him after World Tour but had actually missed Gwen. They then collapse to their knees out of exhaustion and embrace each other, saying that they're "friends forever".
In "You Regatta Be Kidding Me", Gwen saves Courtney from falling in the water. Courtney thanks her, exclaiming "I almost got my hair wet!" They then start complimenting each other's hair, leaning closer and closer to each other with huge smiles on their faces, before being interrupted by Chris.
In "Sundae, Muddy Sundae", the way Courtney looks at Gwen is the exact same way she looks at Duncan in the Action intro.
Sadie and Katie are extremely close and are seen hugging quite a lot in Island. In "The Sucky Outdoors", they each have a moment of gushing over how pretty the other girl is. They also bicker Like an Old Married Couple on occassion with it being prominent in " The sucky outdoors". There is also one moment where they both agree to pee in the bushes... Together. While gleefully chuckling to themselves.
Owen and Justin. Owen is clearly attracted to him since the first episode. He constantly blabs about how hot Justin is or how he wants to kiss him. In one episode of Action, the two hug each other, then let go of each other in awkwardness.
DJ's mom has a very different design between her photo in his audition tape and her appearance in "Celebrity Manhunt's Total Drama Action Reunion Special". Retcon, or does DJ, in fact, have two mothers?
While Anne Maria has confirmed feelings only for Vito, during "Backstabbers Ahoy!", she goes from frowning to smiling when Svetlana comes out and gives her Pre Ass Kicking One Liner.
Mutant shark Fang has a lot of Foe Yay with Scott in Revenge of The Island and All-Stars. Fang continues to beat Scott around even after getting his tooth back from Scott.
When the giant spider in "Finders Creepers" captures Scott and Sam, they are the only two contestants to be wrapped up together, tightly and on top of one another. This causes Sam to comment that he is "definitely overstimulated".
Topher seems a bit obsessed with Chris. Sure, he says it's just because he wants the hosting job, but some of the compliments make you wonder...
Jasmine and Samey seem to be a very popular pairing, since it seems like Jasmine was the only one (besides Shawn) to ever encourage and be nice to Samey.
In the episode "I Love You, I Love You Knots", Dave has to kiss a person next to him for a dare. Seated next to him are Sky on the right and Shawn on the left. Dave first looks at Shawn, who makes a run for it, and only then does Dave turn to Sky. Mind that Shawn, as per his confessional, does not object to the kiss but to the risk that Dave is a zombie trying to get close so he can eat his brains.
In All-Stars, Mal calls Alejandro a "handsome jerk". Especially notable because Heather (Alejandro's love interest) has called him the exact same thing.