Alright then, how about we start with the fact that it's 2015, and bafflingly enough, you're still only speaking in terms of heterosexuality, homosexuality, and bisexuality? Even if we were to consider those designations intelligible, valid, and distinct categories applicable to human beings (and that would be a mean feat), they're by no means exhaustive. Myself alongside the majority of people I know don't identify themselves with any of those labels. Does that mean we somehow evade this strange deterministic system you propose? Are we free to enjoy the representation of any physical relationship between consenting adults somehow?

Even more nonsensically, you're using the term "opposite" gender, as if you think there's only two genders, and that they exist in direct apposition. Moreover, you're only speaking in terms that implicitly exclude people who don't conform to those gender patterns. Assuming that "straight" in this context is referring to a hypothetical condition where those who are designated into a "male" pattern are only capable of feeling attraction towards those who are designated into a "female" one, or vice versa, how does this hypothetical "straight" person react to a person who does not fit into either gender pattern kissing another person who fits into a different gender pattern that again isn't reconcilable in the social heterosexual matrix?

This wouldn't make sense even if we were to assume hypothetically that there are only two genders and three sexualities. It's still demonstrably false. Films and television shows are still made featuring kisses and further physical intimacy between two people of "the same gender" (again, drawing attention to the fact that we are assuming that there are only two genders), and these films and television shows are successful not only among queer audiences, but also among "straight" ones as well. And though you may find "straight" people who are repulsed by or even disinterested in queer relationships, very few "gay" people feel the same way about "straight" relationships, unless they are simply tired of the constant barrage of romantic stories which only operate within a heterosexual framework, which isn't related to their sexuality and more related to their palate.

It doesn't even work from a theoretical standpoint. If your sexuality directly correlated to what relationships you enjoyed watching, that would assume that the only way people experience art is from either a standpoint where they derive voyeuristic pleasure from being an unseen observer to the relationships between the characters, or understand it by directly relating the narrative of the characters to their own experiences. But there are more ways of enjoying a story than just those. It is purely possible to follow a narrative where your only relationship to the characters is one of empathy. Even if you can't see yourself in the same positions as the characters, it's possible to simply be happy for their happiness and for them achieving their hopes and goals. The only way it would be absolutely impossible to feel this empathy for a physical relationship between two people of "the same gender" is if it is being prevented by an implicit or explicit homophobia, which is culturally instilled; not innate or a matter of individual taste.

And on a final note, "gender" and "very simple" do not typically go together in the same sentence unless you add a "is not" between the two.