Men:If your girlfriend/wife has sex or anything with another female, do you consider that cheating?

I was talking to another guy and past relationships came up. I mentioned that my ex gf had another gf while we were together and I knew about it (didn’t care at all) and she hooked up with other girls while we were together (not just talking about threesomes) and he was saying how he’d never be able to be with anybody like that because they’re unfaithful but my whole thing is I don’t see it the same as her being with another guy at all. Two completely different situations, so men, if your GF/wife hooked up with another girl, is that cheating?