The classical Romans were a lot less gay than people think. They thought that homosexual relationships between men (as opposed to just doing a guy in the ass to establish dominance) were effeminate--but they were so misogynistic, they went ahead and romanticized love between men anyway. In fact, they considered it more manly to keep prepubescent boys as sex slaves than to admit you had feelings for a woman--several of the Great Men of classical history caught flack from their peers for having what we'd now consider healthy relationships.

Lesbianism, on the other hand, was considered a form of frigidity, and could be cured by... well, google "corrective rape" and spend some time headdesking, because I'm not going into it. It was also an object of some bafflement by Roman men, because apparently asking lesbians how they had sex never occurred to anyone. Neither, apparently, did they consider that sex didn't necessarily have to involve a penis, because there's some speculation on the topic of how two women get it on if nobody has one. Hypotheses included constant, obsessive dildo use, and one partner growing her clitoris into a serviceable phallus through black magic.