Boyfriend with another girl.....

Here it goes... my now boyfriend and I met 4 months ago. He had a friend that’s a girl that he basically did everything with before me but said he wasn’t romantically interested in her although they met on tinder.... ok. Well anyway, once she found out he was talking to me, she said that she was in love with him, and blah blah. He told me all this, but there’s nothing I could really say or do. I never really heard anything else about her.

A few weeks ago, I found out he went on a day trip with her to a popular fall event about an hour from here, no big deal except he didn’t reply to me all day and didn’t tell me he was going or with her. Had to find out from Instagram. Then the week after that, he told me he fell asleep super early one night and the next morning I see that he was actually at a Halloween party that night with guess who? That girl.

Now tonight he said he’s going to see a movie with her.

I’ve never met her. I never really say it makes me uncomfortable except for one time very passively. Am I wrong to feel weird about this and like something else is going on? :(