Can someone explain it 😩😭💔

I just don’t understand. Me and my daughters dad have known each other since we were 7/8 years old and now were 24 and 22 and have a 4 month old. And I don’t understand why he will have babies with me but will never or doesn’t want to be in a relationship with me.

Like we reconnected in 2018 and had a fling which then obviously ended in me getting pregnant and having out daughter august 2019. But he never expressed wanted to be with me. Like he’ll make it feel that way when were in person but then ill find out he has a “girlfriend” but he’ll still come over to my house and see our daughter and want to lay up and play house together and still have sex and always ask me when im going to be ready for our second baby together. I just dont get it.

Like why am i good enough to have your children but not good enough to be your girlfriend? 😩