I think "cheating" is saying you don't love your partner.
On the other hand, sex is another thing apart from love. I've known swingers who are very happy couples and seem to be in love with each other. When they swing, they each have sex with different partners. As far as I know, probably in the same room. To me, that's probably not cheating because they're not hiding it from each other and they allow each other to do it.
I do know that men and women can have different attitudes. In general (not always), men tend to be driven by a desire for sex and sometimes don't care about getting to know the person. Women, many of the ones I've known, aren't as quick to jump in bed. They have to be seduced or take their time to get to know the guy. Not always. If my wife were single and certain celebs said "let's go", she wouldn't hesitate. Hell, for all I know, even being married she wouldn't hesitate.