Just to educate, Romans didn’t have an issue with homosexuality as long as there was a clear power dynamic. A Roman man could have sex with a younger, lower status person and he would be looked at as virile. The boy would also not face backlash. However as they grow into adults, the “bottom” would be looked at as a woman or unmanly. Caesar was mocked as the queen of Bithynia due to a gay rumor between Caesar and the king, but the making fun wasn’t because of the gay act, but because Caesar was rumored to be the bottom.

I’m guessing two Gladiators going at it would not be an issue for anyone as they were slaves and prisoners. Additionally, Gladiators were extremely sought after as male prostitutes to women of wealth.