What would you do? Am in the wrong?

So my boyfriend recently started flying his son out here for the summer. I told my boyfriend from the start that I felt anxious about him coming down this summer (not saying I don’t want him here because I do, he’s a great kid!) but I was just anxious because I knew since my boyfriend worked nights that I would be responsible for their son. (Him and his ex wife) He came down last summer too but my boyfriend was working morning shifts so we were all together. Anyways, his son has been in the habit of staying up SUPER late, like til the morning (6am) and waking up around 4pm. Meaning he doesn’t get his first meal until he wakes up and eats again super late. I told my boyfriend about this and he said “Just let him, he’s a kid and it’s summer.” Im anxious about this for a lot of reasons but main one being is that I feel like his mom will get upset with me but since his dad is literally telling me it’s okay I feel like I have no right to tell their son what to do. After all this is the second time he’s met me in person. But I also know his mother wouldn’t approve of this…We had a little incident the year before where she basically went off because he was waking up late and eating snacks in the morning but also his dad approved of this. Whenever he asks a question like “Can I?” I always say call and ask your dad.

What do I do? I’m just agreeing with whatever his dad says but I know his mother parents completely different. I feel so anxious right now!!