Sleeping over at boyfriends house

I’m going to be starting college pretty soon and I’m 18. I don’t live with my parents since they decided to move an hour away (give or take) from my school right when senior year was about to start, so I’ve been living with my grandparents. I never have anything to do at my grandparents house but I feel guilty going over to my boyfriend’s house just to come back at 9-10 pm when my grandparents are already in bed. I’d much rather sleep over when I do choose to go to his house (which is only once, sometimes twice a week). I don’t want to bother asking my parents if I can go sleepover at his house while I’m still in high school because I feel like I’m gonna get shot down so I’d rather wait til I start college when I might have a better chance. I’ll still be living with my grandparents but I always let my parents know what I’m doing even if I’m not under their roof. To be clear, my intentions aren’t to go sleepover to have sex. I just want to feel comfortable in knowing I can dose off without getting worried. Besides, we’d be in a room with his younger brother.

A bit of background: I’ve been with him for 3 years and my parents know him very well. My mom put me on birth control as soon as I told her that I lost my virginity to him and we were each other’s firsts. I literally tell my mom everything and I don’t even think it’s an option for me not to tell her where I’ll be spending the night. Even when I’m in college.

(TL/DR) My question is, would you be ok with your 18 year old daughter sleeping over at her boyfriend’s house? And how should I go about telling her.