Cheating is not great. It does happen and unfortunately it happens even more often than expected. It does not matter the gender of the person, everyone cheats if they have it in them, be they female or males. Cheating comes in different forms and it not involves just sleeping with someone else.
There is emotional cheating, cheating when speaking and gesturing in a loving way with someone or there is online cheating. This actually involves chatting with someone online and starting to involve feeling into it as well.