cheating or just crossing a line?

Emma

If you’re boyfriend/significant other tells another girl that they’re pretty/hot/sexy/whatever word they use while with you, is that cheating or just crossing the line? I am in this situation right now. My boyfriend of 3 years told a girl we both know she looked “hot/sexy” & then the next day apologized to her & said he crossed a line & he shouldn’t have said anything (she confirmed he did apologize). He told her this 3 months ago & I’m just now finding out. I don’t know what to do. Half of the people I’ve talked to have told me to leave him, & then the other half tell me that I should stay & work on it with him.

Side note: At the time that he said this we were going through a very very tough time in our relationship & had “broken up” already a few times that week (like the “I’m done f*ck this & then a few hours later we work it out). Our relationship is 1000x better than what it was then & he hasn’t shown any other signs / said anything else to anyone. I’m torn because he apologized to her the next day, said he loved me (to her) & didn’t want to hurt me. But why say it in the first place? Please help me out.

Edit: I do know that a “tough time” doesn’t justify his actions & he told me that. we’ve talked about it & he’s aware that it was wrong & that’s why he apologized to her & nothing has happened since. I just wanted to give some context of where our relationship was.