I have been cheated on once confirmed, and another suspected.

the person I know was cheating was seeing another girl behind my back, and was abusing me in the meantime to kept me down and make me think everything was my fault, when in reality it was just to cover up his cheating. i never suspected a thing until his roommate told me about it.

the other person I can't confirm was cheating, but all signs lead to such.

these kind of people do not change, and in much time away from them, they have proven that.