How should my mother-in-law handle this problem when she finds her son-in-law interacting with her ex-girlfriend Weibo?

what can I say? If I find my girlfriend having an affair with that man, I won't ask him impulsively at first, say how are you? What if it's a misunderstanding? It won't end well then. Look at each other's QQ now, Weibo. It's easy to make the other person feel that you don't trust him or her. ...