When they add, and persuade themselves, they can not only retain their faith but deceive themselves to believe their behavior has Gods approval, they've created a psychological ‘storm’ within which cannot be maintained without serious consequences.
Generally, if a true believer, the pressure is so great they eventually seek help to leave these practices....or they succumb to a complete seared mind unable to find the faith within they once might have known.
For the most part most homosexuals are not Christians, rather they simply lay claim to this in order to deceive the Christian community and gain their approval and recruit others to become like them.
I've not seen any data, one way or the other; but common sense tells me that they KNOW they are doing wrong, and desperately want out of the situation they find themselves trapped in.