DD's Boyfriend

[Carsarelife]

DD has a boyfriend who comes over twice a week roughly. They are both 18 and both at college they also work together although don't see each other much at work. He lives 1 train stop away.
I just asked DD what time he would be going home and she said he would be getting the last train at 11:45pm

AIBU to think this is so late for a week night? Everyone has college and work tomorrow and my youngest has school tomorrow. I know they are 18 but I want to say 11pm is late enough and in future he needs to be gone by this time.
Obviously I'm mindful about not wanting to upset everyone and not to be unreasonable

Probably because they’re being intimate in the bedroom and the younger sibling isn’t allowed in/doesn’t want to be in.

OP, I’m 24 and had a boyfriend at 18 who was always over at mine too. We had a very intense relationship in every possible way and looking back, I do regret that and wish my parents were less lax. He’s a nice person but when you’re 18, it’s hard to regulate your emotions and deal with a “serious” relationship whilst you’re still trying to figure yourself out. When we’d fall out or he was upset about something, it would impact my mood and make it hard for me to focus on study etc.if my parents established a boundary of him leaving by X time, or only allowed over on Y days, or only staying in the kitchen/living etc then I think it would have been easier for me. Sometimes as a parent you need to step in. My parents were happy to invite him over, socialise with him, cook dinner for him etc so it’s like I never got breathing space.