Me and my boyfriend have a friend (a girl) between the both of us. She’s very flirty and posts suggestive photos sometimes. Idc care about that bc she can do what she wants and she’s my friend. However, my boyfriend just recently told me that he’s been sharing all types of details about our sexual life with her. He also liked her photo of just her in her underwear with an all the way open shirt showing her half boobs. When he visited me he wouldn’t stop texting her and talking about group calling her. He woke from our nap together saying “we have to call her”. One time she picked up on the toilet and he was laughing asking her if she was on the toilet while she was just trying to tell him to call her back. He said she was in a bra... I have a hunch that he’s developing feelings for her and my hunches usually aren’t wrong. Am I overreacting? Should I set some boundaries?