The available evidence strongly suggests that sexual orientation is genetic. Since their is no choice in the matter, there is no ethical issue. However, since the majority of arguments against homosexuality tend to relate to religious norms it is extremely unlikely that there would be any such issue even in the eventuality of there being a choice. In particular, it can be observed that most religious norms of this kind tend to be founded heavily on a morals of abstinence
and as such are of diminshing utility in any modern context. It may also be observed that such norms tend to be heavily UTistic.