Bob identifies themself with a social construct - a nationality, a religion, a subculture (e.g. "Nice Guys"), or whatever. As such Bob feels Alice is obligated to be with him, one way or another. Perhaps, given that they identify with the same construct, she will be a 'traitor' to 'their kind' if she does not date or marry within it. Or maybe he just feels that by belonging to the category he 'deserves' her more than someone that does not. The former self-justification often goes hand-in-hand with the latter. If Alice complies, she might even discover that Bob is willing to take his sense of entitlement further still.
There are several basic ways in which Bob can justify his sense of entitlement, all of which can just aseasily apply to women as well:
A: Who he is. For example, "She must sleep with me because I'm part of Clan X and a woman of Clan X must always choose X over Y".
B: What he does. For example, "She must sleep with me because I repair her television and listen to her drama, therefore she must give me something in return, and this can only mean one thing".
C: What he doesn't do. For example, "She must sleep with me because I wouldn't rape her", or "She must sleep with me because I normally abstain from sleeping around".
Ai No Kusabi: Iason, the highest ranking Blondy of the ruling class, has this general attitude about his low class "Pet" Riki. That he's entitled to sleep with Riki for no other reason than it's his right and the fact that Riki is a non-citizen so therefore has no reason to follow the strict No Sex Allowed laws with him. At least, that's the excuse he uses.
Puella Magi Madoka Magicainverts (and may deconstruct) the trope with Sayaka Miki. She does lots of things for her hospitalized friend Kyosuke and seems to view herself as "an ideal white knight(ess)" in regards to him (despite the guy being a massive case of Oblivious to Love), but she actually considers herself unworthy of his affections; she is seen calling herself "a bad girl" when alone for wishing to be loved, is rather disturbed when Mami warns her about the trope, and she also never ever can spit out her love for him. And so, Sayaka being in this situation does NOT mix with her other severe problems (black and white view of the world, nonexistant self-esteem, the terrible changes brought by the Magical Girl lifestyle, etc.) and it becomes one of the reasons why she splinters badly enough to have a Face Heel Turn and become a witch. So in the end, Sayaka does lots of things for Kyousuke, but her view of love is so extremely unrealistic and idealised that she hates herself for even wanting to be loved by him. It's clearly seen in the Grand Finale, when Sayaka's soul decides that she'd rather stay dead and go with Madoka than interfere with Kyousuke and his girlfriend Hitomi, the girl who was loving but also assertive enough to spell her feelings for him when she had the chance.
In Bitchy Butch, Butchy herself is often a (female) example of this trope, ranting about how random women ought to "be loyal to their gender" and have sex with her rather than with the men they are in love with.
In one Mega Python album, the male protagonist demand sex from a random woman, using the argument that she must sleep with him because he's gay. When she dispute that he'd even want to have sex with her if he's gay, he replies that he's considering getting turned straight.
In one strip of Inrutat (by the same guy who makes Pondus,) a male dinosaur is pleading the Type D with a female dinosaur, as the Extinction Level Event Comet is blazing down from the sky.
In City Of Dreams, The white prince seem to have more then a little bit of this mindset, but this turns out to be caused by the fact that he actually IS her boyfriend - yep, Christine's sexually repressed Heteronormative Crusader real life boyfriend is a dreamer too, but as much as he'd like to tell himself he's only there to rescue her, he did in fact end up in Morrigon of his own accord...
Debated in Female Perversions, a debate played for horror: A particularly creepy woman is holding a little lecture about how a woman "must" be an empty canvas for men to project their desire on. Her niece's (slightly delayed) response is to start cutting herself - carving the word "love" into her own flesh and explaining that she meant to write "hate". Maybe she didn't know the difference anymore?
The case for Chad in Tucker And Dale Vs Evil who believes that he is entitled to Allison because she and him are special and goes crazy when she falls for Dale who he sees as a hillbilly and beneath him
In the Johnny Depp Dark Shadows movie, Angelique argued that she and Barnabas belonged together because they were both monsters.
The Turner Diaries argues that women should not sleep with those of another race, claiming that those who do so "defile their race". The male white nazi "heroes" even murder a lot of white women, hanging signs saying "I defiled my race" on their corpses. (And no, calling the protagonists "nazi" is not Godwin's Law - the book is written by a neonazi for neonazis.)
In the most recent book of A Song of Ice and Fire, practically none of the men looking to marry Daenerys to make their lives and respective likelihoods of becoming king better think even for a second that she might say no. Aegon Targaryen VI has to be flat out told by Tyrion, "She has her own claim to the Iron Throne, her own kingdom and, oh yeah, the only dragons in the world and you think she's going to give that up for you and your fuck-all?" for him to change his mind from "Of course she'll marry me, I'm me!"
In Twilight, Jacob starts to develop this view towards Bella. He argues that he was there for her when Edward was not, and thus she should dump Edward and switch to him. This leads to him forcibly kissing her twice to show her what she's missing, a tactic which works on her. This trope also is implied to be how imprinting operates. When a werewolf imprints on a girl, everyone - from the werewolf himself to the rest of his pack to everyone who knows about imprinting - expects the girl to come to terms with what's going on and hook up with the werewolf. Jacob even says that while the girl technically has a choice in the matter, he doesn't see why she would choose to turn down the werewolf.
Peter Cambell in Mad Men does Type B with a German au pair that his neighbours hired. He goes through some trouble to fix a dress with red wine or some such spilled on it, but it's only after he returns it that she tells him she already has a boyfriend. Her reactions indicate that it was naivety about his intentions rather than an attempt to use him, but he still forces himself on her a bit later. This comes back to bite him when the neighbour finds out.
Cher Lloyd's "Want U Back" is about a girl who expects her ex to obediently leave his new girlfriend and fall back under her thumb, even though she's the one who dumped him in the first place, for no other reason than "I had you first."
Taylor Swift - "You Belong With Me" is about a girl who believes she deserves the boy better than his actual girlfriend does, because she's the only one who "understands" him.
N Sync - "Girlfriend" is about a boy who is trying to convince a girl that her current boyfriend doesn't care about her and that she should hook up with him instead.
Avril Lavigne - The infamous "Girlfriend" song is a bout a Jerk Ass "punk girl" who hounds a boy who's already taken, insists that his much more homely girlfriend is "like whatever" and tells him that she's a better lay so he should date her instead (while said girlfriend is constantly punished for being upset due to that). Lavigne says that she intended to either poke fun or call out girls who do such shit, but the video to the song plays this trope infamously straight.
Girl Writes What, in this video, discusses how the trope is often invoked in defense of reprehensible behaviour on the part of the pursued. She focuses particularly on analyzing and deconstructing the claim that "Nice Guys" are Types B and C.
The princes of Morocco and Aragon both feel this way about Portia in The Merchant of Venice, and, when they each have to choose a casket to win her hand in the Engagement Challenge, they both contemplate choosing the silver casket, labeled "Who chooseth me shall get as much as he deserves." Morocco sums their logic up nicely:
"As much as he deserves"; why, that's the lady,
I do in birth deserve her, and in fortunes,
In graces and in qualities of breeding,
But more than these, in love I do deserve.
What if I strayed no further, but chose here?
He doesn't end up choosing that casket, but Arragon does. They both get sent home, and Portia ends up marrying a poor gentleman below her station.
In The Taming of the Shrew, Gremio believes he's entitled to Bianca because a) he's her father's neighbor, b) he was suitor first, and c) he's rich. Of course, we're not meant to like him, and she ends up with Lucentio, a much more palatable, lucky-to-have-you suitor.
Despite his massive Draco in Leather Pants fandom and those who genuinely sympathize with his admittedly hard lot in life, The Phantom of the Operaowns this trope in his relationship with Christine. Much like the "Not-Really-Nice-Nice Guy" mentioned below, The Phantom misrepresents his intentions when he begins to mentor Christine disguised as the ghostly "Angel of Music" her late father sent to her, using this as an opportunity to stalk her and lure her towards loving him in return for the help he's given her with her theater career. When Christine refuses, frightened a little by the Phantom's deformity and a lot by his his real personality, The Phantom... reactspoorly.
In Umineko no Naku Koro ni, George confesses that he used to be this sort of guy, assuming he should be more popular with women because he "treated them well" and that he wasn't because they have bad taste in men and prefer jerks. He hit a turning point when he realized that Battler was getting more attention from Shannon and other girls not because he was a rude punk, but rather because he was an outgoing and genuine guy who didn't put up a "Nice Guy" front simply to win over girls. George admits in hindsight that his past behavior was pretty douchey and entitled, and he'd rather forget he was ever like that.
The protagonist of the game Next Station: "Mary should love me, I loved her so much and I was so niiice to her!"
In Persona 4, Adachi feels entitled to have both Mayumi Yamano and Saki Konishi (who is a high school student) because they both apparently date around. In Mayumi's case, she was dating a married man, but in Saki's case, it was an issue of misunderstanding. He kills them both.
In Visual Novel/Fate/stay night, Gilgamesh decides that Saber is his destined to be his wife simply on the basis that he's so awesome that he deserves to have whatever he wants. Nobody else quite agrees with him on this, especially not Saber.
A possible and popular interpretation of Braid's main character's behaviour, the ending level all but stating that his advances towards the princess aren't exactly invited.
Both fans and haters of SieKensou say that he thinks Athena Asamiya owes him sex since he's had a massive crush on her from early times in the franchise. The haters insist that he's an entitled shit who wants a pityfuck and would rape Athena if he could, the fans reply that he does deserve Athena's affections better for supporting her and call her Ungrateful Bitch. In reality, Kensou veryrarely falls into this: he's shown as being comicallyjealous when it seems Athena may not like him — but in the counted times when she does need help, he helps her out WITHOUT any second intentions.
Oddly enough, a later storyline features a flashback to Davan in high school, where he has the same basic attitude about a girl he tutored. In this case it was his sister Dahlia who made him realize how his perspective was messed up.
Becca in Peter Is The Wolf is this, bordering on Yandere for Peter. The only thing holding her back is that wolf!Sarah is nearly twice her height and can fling Becca out of the way... or possibly worse. She's a partial deconstruction though — her history of being regularly raped by her father gives her possessiveness to Peter a Freudian Excuse.
Homestuck: This is a common fandom interpretation of Eridan, albeit in a more mild form: he was Feferi's moirail for a long time and then was quite displeased when she not only wasn't interested in a romantic relationship but wanted to break up their moirallegiance as well. However, while he did later kill her, there were extenuating circumstances, so it's a bit ambiguous. (One Fan Fic portrays him as aromantic in a society where not being in a relationship is a capital offense and genuinely unable to grasp why she would prefer Sollux over the "logical" choice of him.)
Cronus, on the other hand, is a Nice Guy tm all the way down. He insists that he's a sensitive soul and only wants to be there for everyone and gets very pissed off when they don't want to be around him...but makes it very clear that the only reason he hangs around anyone is because he thinks that means he deserves to sleep with them and doesn't give the slightest shit about their feelings. All of this combined with his refusal to take no for an answer unless there's seriously no other choice makes for a very creepy character.
Shishi from The Law of Purple feels this way about Blue because she comes from a seriously misandristic culture and has "dibs"
Heartlessbitches.com shows how this trope can apply to self-proclaimed, vocal "nice guys". Basically, these are the people who think that being friends with a woman, and listening to her talk about stuff/accompanying her on shopping entitles them to be her romantic interest. There is also the double standard that these sorts tend to want attractive women, but dislike women who date attractive men.
Are you fed up with your Male friends who are looking to date a woman with the appearance of a supermodel, and yet they continually whine about how "women don't like nice guys - they only want good-looking assholes"?
The Nostalgia Chick once had a long rant about what an asshole Todd In The Shadows was because he didn't "want her love and affection". Made all the funnier because Lindsay and Todd are a couple in real life, and apparently quite happy with each other.
In Jacksfilms' "Dubstep Solves Everything 3" music video, Jack and Mike fight over who gets "the girl on the bench", ignoring her opinion in the matter. Upon winning the dubstep battle, Jack says, "To the victor go the spoils," then drags her off by the hair despite her loud protests. In this case, the (parodied) message is that, "because I won a battle over her, she must date me."
In Megamind, this is a big part of what makes Hal so creepy.
Gaston in Beauty and the Beast seems to expect Belle to just fall into his arms because... well, he's Gaston. When she finally makes it clear that no, she's really not into him he... doesn't take it well. The other girls in town have no problems with falling into his arms should the opportunity present itself, because... well, he's Gaston, so it's a double insult to him.
"That makes her the best! And don't I deserve the best!?"
Rather creepily, most of the townfolk believe this trope, thinking that Belle is "crazy" for wanting to get away from her stalking because she should feel lucky to have the attention of such a great guy!
Beast is this (in a more platonic fashion) at first. When Belle doesn't want to eat dinner with him, he yells at her to go ahead and STAAAARVE! A good part of his Character Development is about him dropping this really bad trait, which culminates with him willingly letting Belle go back home, which he does because he loves her.
In Superman The Animated Series, the Kryptonian criminal Mala is freed from The Phantom Zone by Superman because he believes that she had been Just Following Orders from her superior, Jax-Ur, and that her sentence had long been served. He teaches her to use her powers under a yellow sun like he has, and she naturally assumes that since they are the last two Kryptonians, she and Superman are mates. When she discovers that Superman is not interested in her and, instead, wants Lois Lane (a squishy human), she is disgusted and enraged and releases Jax-Ur... who turns out to also be her lover.
Quasimodo from The Hunchback of Notre Dame has more innocent shades of this towards Esmeralda, particularly if one subscribes to the belief that the gargoyles represent aspects of his mind. They continue to try to convince him how Esmeralda will surely be romantically attracted to him for all the times he's helped her out, and then belittle Phoebus when it becomes apparent that she loves him instead (which actually happens because he sees her as her own person). Quasi does overcome it, and gives his blessing for Esmeralda and Phoebus.
Frollo does this too, in a far creepier manner. Since Esmeralda is "a sinner", it's his job to set her straight, and if she refuses him she shall be burned at the stake.