Can a gay Jehovah's Witness help but to be gay? NO. He can help but to be a JW.
In order to be a JW, that gay male must refrain from showing approval of homosexuality and must refrain from premarital sex, whether with males or females. If he wants sex, it would have to be post-marital hetero-sex.
If he cannot refrain from sex and cannot refrain from showing approval of homosexuality, then he must stop being a JW.