https://d1ai9qtk9p41kl.cloudfront.net/assets/mc/_external/2016_06/poll.pngApproximately the same percentage of American Muslims oppose gay marriage (52%) as American Christian Protestants (53%).
So if you're going to say Muslims don't support gays, you're going to have to include Christians, too - or at least Protestants.
Now, if you're talking about international support of gay marriage or gay rights among religious groups, then both Muslim and Christian's opposition to homosexuality increases dramatically and uniformly outside of America and Europe.
This entire "Pick one" between Islam and homosexuality that I've been seeing Trump supporters parrot from /r/the_donald or shit sites like Breitbart is funny because it assumes that all of a sudden Conservatives/Christians don't care about gay rights or gay marriage anymore (they still do), and it is a veiled attempt at disparaging Islam while leaving Christianity out of the discussion.
If you want to criticize how religious groups treat homosexuals, then you MUST include Christianity. Christianity is the largest religion in the world and contains an anti-homosexual sentiment. I will say that the Left's recent behavior in criticizing Christianity but defending Islam is also pretty stupid, as it seems pretty reactionary to the far-right movement of America (enemy of my enemy is my friend and so on) and Liberals really should be probably be finding problems with both religions in the context of advocating for more human rights.
Trump supporters' attempt to "checkmate" Liberals by making them support Islam or homosexuality is foolish, especially for atheists and agnostics who see problems with all Abrahamic religions.