Outsider Perspectives?

TDLR; We’re both 30 and been together for two years. He lives at home with his parents. His parents place minor-aged restrictions on him that I feel blocks our growth. Maybe I’m not seeing and understanding it correctly? Maybe there’s another solution?

We are both 30. He lives at his parents home, because the backstory is how he’s been structured to think of success in life (purchasing a home with 50% down, needing a different degree after his first degree, etc). While I’ve helped him understand there’s other options out there, we have another dragon that appeared.

Because he is at home, they still place very minor-aged restrictions on him. I can only see him once a week; nor he cannot spend the night; he’s not even allowed to work overtime that starts to cut into the night. If he attempts at any, it gets extremely violent in words (loud argument, threats, nobody wins), so we gave up all those ideas, while we kept trying to find a common ground hobby we could mutually meet elsewhere than either of our homes.

We decided to choose bowling. It wouldn’t take very long, we would spend a little time in the middle of the week together at another location, we thought we very much had it made. Until… the mother found out that we were planning this. She tagged teamed with the sister (25), and said he had to bowl with his sister, no matter what at another location, and not me. When I asked him why, he said because his family is tight knit. I told him while I understood that, we had thought long, hard, and set a lot of plans up for this, and it was unfair. I am not trying to ruin his family by any means, but I am trying to bond with him better, find more time with him, and the family seemingly ruins it. I had also felt like she should be the one that would end up secondary or even added directly onto the activity we were doing, where we were doing it, if she must, but that’s now how it unfortunately works.

I feel at 30, we both are old enough we really need to bond better for long term relationship planning, build some mutual social circles, and enjoy some hobbies to grow together.

I don’t understand why the little sister takes priority at his age and her age, and wipes out anything I built up. However, in trying to cope with these sudden change in plans, I’m trying to figure out what can be said to him of the situation, what can repair, alternative suggested, or if I’m just not looking at the situation properly? I feel like it’s been an intentional thing that’s been put in the way of him building anything more with me.