Sleeping over at my boyfriends place

So I am 21 years old and still living at home with my parents until I finish school and can save some money for my own house. Now my boyfriend is 22 and also lives at home and his parents are super laid back and don't care if I stay over or anything and my parents are the complete opposite like wanting me home before 2am and stuff like that. So how can I convince my parents to let me stay the night with him. And I'm only asking because I want to respect their rules but still feel like an adult at the same time