Question re: gay sex

If Bob had sex with Jim, yet Bob had no sexual attraction to Jim and just fucked him in the ass to get a sexual release, does that make Bob a homosexual or not?

Technically it doesn't make Bob gay, but why the fuck didn't he just jerk off?
I can get why fathers would want to have sex with their daughters just for release, because daughters actually have a pussy that's better than a hand, but an ASS??? COME ON!