HOMOSEXUAL, because there's nothing GAY about it.
The percentage of men who are simply incapable of copulating with a female is very, very low. Such men should not marry women, and cannot, since if they cannot successfully complete an act of "vaginal" intercourse, the marriage is null under both civil and canon law. Meaning, there is in reality no marriage.
Any man who vows himself for life to one woman and then gives himself to a different partner, man, woman or dog, is an adulterer, no matter what the LGBT Bacon-Lettuce-and-Tomato commentariat says, an no matter whether there was a divorce or not. He's a liar and a vow-breaker. That's the "identity" he's taken upon himself --- the one that really matters.