It's a little more complicated, though, if it's a natural parent who's gay. Or a single gay relative (family kin) adoption. Novelist Walker Percy and his two brothers were all three adopted when they were half-grown boys, by their cousin William Alexander Percy ("Uncle Will") and he apparently did a very good job raising them. Though he was homosexual, he was not, however "openly gay." He was simply a bachelor, didn't have any homosexual vice going on inside the household.
The most dangerous threat a child can face, statistically, is "mom's live-in boyfriend."