Homosexual desire is no different that Hetrosexual desire in this respect, everyone has his own set of likes and dislikes. Some guys go all nuts for tall blondes, some guys go all ga-ga for olive skinned, dark haired lovelies and some (like myself) cannot resist a light skinned black woman. Homosexuals go all nuts for another butt pirate. You don't HAVE to go that way.
As much as I am attracted to black women, I was married for a long time (over 15 years) to a latina.
If there is a gay gene then there is also a foot fetish gene, a beastiality gene, and you...well you get the picture.