I think the fact that your own sexual preference really has no effect on other people should be sufficient to say that the decision should be your own. Sure, gay people shouldn't be allowed to sexually-harass people, just as heterosexual people shouldn't be allowed to do the same, the same thing really applies to all concerns regarding your interactions with homosexuals. They should be restricted by the same laws and social constraints that restrict heterosexuals. I have no problem being friends with a person who happens to be homosexual, though perhaps I would have a problem if they openly thought of me in a sexual light. However, that doesn't mean I'd have a problem with the concept of homosexuality, just the concept of a person expressing unwanted sexual interest in me. As you can see, the same thing applies to hetero-friendships. If a man and a woman were friends, and the man (or woman) began expressing unwanted sexual interest to the other, the reaction would be the same. The reason most people are against homosexuality is because they don't fully grasp the fact that their feelings are not regarding homosexuality itself, but the thought of homosexuals committing various unwanted sexual advances towards them (in various ways). People say they feel uncomfortable with the fact that another person of the same sex may be fantasizing about them, but really most people would feel the exact same way at the thought of a person who they themselves do not think of in a sexual light, thinking extremely sexual thoughts about them.
Another problem with society being more open to homosexuality is that the media has implanted the concept of homosexuals being hypersexuals into the minds of the populace (not through any conspiracy, but just through endorsing stereotypes in tv shows for comedy, for example). As a result, people often think of homosexuals (especially homosexual men, to whom most of the prejudice is directed towards), as people who are incapable of seeing a man and not imagining having sex with him, as well as being uncomfortably open about these fantasies to men around them (i.e the gay clothes salesman in Rush Hour 3). In reality, plenty of homosexual people are just as discreet about their feelings/fantasies as you'd expect a heterosexual man to be regarding a woman.
Now, I did say earlier that a man might be just as unnerved at the thought of a woman, to whom he is in no way attracted too, fantasizing about him. This may be not entirely true, but this discrepancy is again, the result of popular societal opinion regarding homosexuality. Society expects men to take the dominant role in sexuality. They are supposed to be the ones doing the courting, and most importantly, they are the one's "doing" the woman, in the sense that it is the man in charge of sex, and that the man obtaining pleasure is more important than the woman (though in recent years, it is becoming more common for sex to be for both partners pleasure, the man being expected to satisfy the woman, just as much vice versa). Therefore, the concept of a man playing a submissive role is considering degrading to his masculinity; it makes him less of a man. Due to these common feelings, a man's reaction to another man fantasizing about him is disturbing, he feels as if he's lost some of his "manliness" for being the subject of such desires, and hence has to regain it through aggression, and distancing himself from the man allegedly fantasizing about him. This is further proved by the observance that women tend to be less bothered by the thought of another woman fantasizing about them, then men do. This is because many women have been raised to believe themselves to be in the submissive role, so to have another women fantasize about them takes nothing away from their dignity, and in fact could increase their own feeling of being beautiful and desirable.