I'm just curious- has anyone here ever cheated on someone before and if so what was the reason behind it and did you regret it?

Obviously only share if you want to. I've never cheated on anyone before and I always feel like you should just breakup rather than seek other people, though I'm just curious as to the reasons someone who has cheated might have since it might not be as black and white as I feel it is. Not condoning cheating or anything but just trying to understand it I guess.