Dating a man with 3 kids

So, I began dating a man with 3 kids. He has an 8 year old boy, a 7 year old girl, and a 3 year old boy. I have no kids. The guy is really cool. I like his kids. However, I would like to be able to spend more time with him alone and I also don’t think he’s a good disciplinarian. So, the children’s mother is engaged to another man. They are supposed to split the kids 50/50, not court ordered, just what they agreed to. At first, this is what was happening. He had them one week, she had them the next. Now, she never gets them. She will just tell him, she’s busy or she has plans with her fiancé, or will bail last minute to get the kids. He is a nice guy, he just always says okay that’s fine and keeps his kids longer, never holds them accountable. What sucks is, he lives in a 1 bedroom apartment, and it’s just him and the three kids and me, if in over. This is temporary. He is supposed to move to a bigger place within the next 6 months. It wouldn’t be so bad tho to be in the presence of his kids if he was a better disciplinarian. For example, I’m off of work at 5, so is he. He picks up his kids and cooks them dinner when they get out of school. I may not come over til 9pm. He has small kids, and he lets them stay up til like midnight. I feel like at some point in the night, I should be able to spend alone time with him because, the kids should be in bed. The 7 and 8 year old may be in bed by 11, but they’re up on the phone or playing PS5. The 3 year old is usually asking for juice or sandwiches at mid night and just as up as we are. And then he tells them go to bed and they don’t listen. Especially the 3 year old. They always say no to him and answer saying what. At 3, almost 4, I feel like you know a little bit of right from wrong, but he will always say to other kids, “he’s a baby” he doesn’t know better. And I feel like that just reinforces his negative behavior. On Christmas, the 8 year old got a two soccer balls for Christmas, and the 3 year old started crying saying he wanted it, and he told the 8 year old to give it to him because he’s a baby and he’s the big brother. At 8, you’re a child. I don’t think this was right and to me is still reinforcing negative behavior. The 3 year old will yell at his dad and tell him what to do. Like the other day, the 3 year old knows how to put in his shirt, but he’ll scream at his dad and say”no you do it” when asked. This can be about anything. And the dad will just do it. To me, this is unattractive and weak. I don’t have kids, so maybe I just don’t understand. But I do want to have kids and I feel like our parenting styles will not match. Like he lets his kids listen to Lil RT. If you don’t know who he is, he’s an 8 year old who raps about sex and gangs. What do you guys think? Am I wrong? Any advice? Is it my place to bring this up to him? I know his ex had issues with him because of his parenting style. Nevertheless he has a big heart and he’s good to me and I like him a lot. I just don’t know what to do.