What am I doing wrong

My bd cheated on me a lot in the beginning of our relationship. We went to therapy, he owned up to everything. He also admitted that he would be extremely nice to me after he cheated cause he felt bad.

He just recently started being an Angel to me. Like the sweetest. Of course my first thought is “he’s only being nice cause he’s cheated again”. But I pushed it aside. I was actually bragging to a friend bout how nice he’s being and she says “oh gosh what he do.” Assuming he cheated cause he’s being nice cause she knows his past.

So I go to him respectfully and tell him what she said and how im having feelings about it. He goes on to say im dumb and weak minded for letting her get to me and that im a bitch.

Should I have just kept my mouth shut?