AIO my boyfriends reply to me being upset about him slipping into women's DMs

He's been replying to this woman's stories who is obviously attractive, calling her 'cool' and 'lovely' even tho he's never met her and she doesn't reply to her.

Hannah is his best friend, and I have no problem him being friends with her. She has a boyfriend and also doesn't post cleavage on insta. Not that that's something bad, it just makes it easier for me that she doesn't.

Alison Janet and Susan are old women at his work who he talks to lol.