Ex-boyfriends frequently chat with girlfriends. Is it interesting to my best friend?

The most important thing between lovers is trust and understanding, but you can't see the problem just by these two dialogues, because I'm not sure if this is a dialogue that you add some subjective emotions and easily understand as his betrayal. Try to communicate, don't question, don't force, don't be emotional, and women had better stay rational at this time. Pay attention to his attitude and tone when he speaks. A man will often fall in love with multiple women.