Me and my bf of 3 and half years have had ups and downs (the usual) we are both 20 he is older by 11 months -

Long story short not ment to speak to this girl she’s a flirt all of the above she doesn’t acknowledge anyone’s gf nothing your a ghost - basically not a girls girls and would do anything to get a lad and ditch you) not ment to talk he does and he says I can’t come to your birthday I’m working .. he then continues to ask Qs like is it a dj / band and I haven’t even asked anymore after that because I was so upset that he continues to talk to her - second time now- when I try express he either says what’s with all these fucking Qs I tell him well bc I would have never of known u less I asked you ( I found out from a friend he spoke to her he didn’t tell me ) and he says “ya ya ya ya” when arguing like he’ll send the message ya one after another before I even reply , he said “your so fucking annoying “ omfg “I actually can’t be arsed “

What do I do 😢😔