according to you, then, kissing, oral sex, anal sex, and a whole host of other sexual behaviors which are non-reproductive (but acceptable in straight couples!) are okay. So then, we must ALL have "something wrong with our brains or hormones". Also, some animals (monkeys, dolphins) behave in sex for pleasure. So sorry, but your argument isn't a very good one.
Another point you make is that gays try and "brainwash" straight people. That is ridiculous- do you mean brainwash as in demand the same legal rights and to exist without harassment? I guess you must think that African Americans "brainwashed" the US too, when they secured their rights. Same for women.