Look if you take a break from your partner for whatever reason only to find yourself in bed with someone else, that’s cheating. No no no it’s not fair game unless both the bf and gf has discussed this. It’s even worse if the person who is cheating is secretive about it. I mean ig you’re doing nothing wrong while on break why be secretive about it.
Bottom line is those who seek a break from their spouse sometimes wants to have his/her cake and eat it too. I personally wouldn’t want to get back with someone who became intimate with another human being while we were on “break”.