If he regularly hates on homosexuals and yet he visits gay dating sites, I'd take the subtle route and the next time he "hates on homosexuals", I'd say - you know, I read that they once did a study on anti-gay and ok-with-gays men and the study involved erections and watching gay porn. The anti-gay men came out with the biggest hard-ons. And then - say you're ok with gays and ask him a direct question - such as - what's your opinion about that study?
Then, keep it up - such as What do you think about Willie Nelson's new cowboy song about gay cowboys? Think there's any truth to all these cowboys secretly fondling each other?
Then go further - I hear that anal sex feels really good - my girl really likes it. Just seeing how she reacts, I could see how gays really get into it.
Then - you know, I was talking to an older straight friend of mine - and he told me that back in the day - guys use to do circle jerks all the time - do you think there's some homosexual tendencies to that?
That's what I'd do . . . But then again, I like fucking with some people.