You can be both Christian and openly gay.
What about the part of the Bible that says sodomite's are going to Hell and should be stoned to death. ......
Or the part of the NEW TESTAMENT that says that once you've accepted Christ you're supposed to at least make an effort to *sin no more*?
I don't think they are being sinful at all.
The hate and ignorance thrown at the gay community is the sin. Hiding your hate behind Jesus is a sin. Failing to love your neighbor as yourself is a sin.
And you try not to do those things.
However to embrace sinfulness and to proclaim that it's okay is an affront to God, at least according to the bible. We all sin, but we don't take the stance "Yeah we sin and we're going to keep doing it because we like it." That's an indication that you aren't really saved..and it's also tempting God.