Am I wrong to think this?

Okay so my boyfriend (we started a relationship and have been together for 5 months but know each other for 8 months) was going to a a town where he used to visit a lot so he has a lot of friends there ! And he’s hanging with them a lot ! Or with his best friend and this girl ! And he was like kinda ignoring me all the time he was there !(he told me like the other week that he always opens my snaps when he thinks of me ) He sent me like one message a day or didn’t open my message but he was online and stuff like that !

But okay ! He comes home after 2 days ! And he’s being kinda distant! And always talking about the girl he was with ... and I’m like okay ! He shows me pics of her and then he says

“I was thinking if we ever have a threesome can this girl be the third person, she’s bi”

And I said” maybe”

But okay ! We go out and hang with our mutual friends and then we go home and are about to have some intimacy ;) but he like doesn’t seem like he’s enjoying it . So I stop and ask him if he’s ok ! And he says “ yeah just thinking”

After we finish he reaches for his phone and starts snap chatting the girl ( we usually cuddle for like 20-30 minutes after sex ) I just close my eyes and don’t think about it, then he goes on her insta and starts looking at her photos and like I mean looking and says “ I mean she’s pretty,“ and then turns the phone slightly to me but I just nod, he then starts to cuddle me and then he like sighs and I ask him if every things ok and he says “idk , I don’t know what I want ?”

I knew he was talking about the girl so I said “ what of you mean”

He’s like saying” I don’t know how to say this but, I kinda like the girl I was with yesterday, I’m not breaking up with you but I kinda want something with her” . I start to tear up but just listen to him and he keeps talking about the girl, and like giving me hints like he kinda wants me to break up with him, so I like ask him if they did something together and he said “no but she was trying to make a move on me “

Idk I was kinda mad at him but also my self ! He’s still really distant and me to kinda ..... I’m just sad ? I really love him and he likes me ? Idk ! I just don’t know what to do ! Should I be mad at him? Sorry for the long read !