Relationships with exes

So, here’s my story.....

I’ve been with a man for almost one year. We have both been divorced for over 3 years. He has one child who is in high school. Every Wednesday, every other weekend, and pretty much anytime his ex wants to go out of town, he keeps his son. He goes to her home, aka their former marital home for ALL visitation. I’m very uneasy with this arrangement. I’ve expressed my feelings, as The last two relationships that I was in ended when the guy ran back to an ex. I’m not really comfortable with it. I’m pretty sure they are buddies, just based on things he had said. He has been saying that things need to change, pretty much the entire time we’ve been together (a year on Dec 31). I guess I could see why an arrangement like that would be beneficial to a toddler or small child, but he’s an older teen. Thoughts? Opinions? Advice? I love the relationship and hate to see it end, I just am not sure it’s healthy for me, and he seems to make light of it. 🤷🏼‍♀️