If you believe in small government, individual liberty, and all the other things that conservatives traditionally believe, then equal rights for gays naturally follows. As evidence I give you the British Conservative Party's leader (and probably the next prime minister), David Cameron:
[N]o-one should be in any doubt that the Conservative party abhors homophobia, that we support equal rights, that we support civil partnerships, that we think that part of being a strong central right party in Britain today.
One of the bedrock issues is being in favour of proper equality for people whether they are straight or gay, or black or white, or men or women, or whether they live in the town or the countryside or whatever God they worship - important points.
He's the Conservative Party leader. That's what a center-right politician looks like everywhere else in the world. His positions are entirely within the foundational beliefs of conservatism (and liberalism, of course).
Incidentally, the interview quoted above was with—wait for it—Gay Times magazine. Now stop, for a moment, and consider the crashing improbability of Sarah Palin or John Boehner sitting down with the Advocate and you start to see how out of touch with conservatism the Republican leadership really is.