Help!

So I’m 20 and I live with my dad and step mom and littlest sisters. Due to my dad becoming disabled while I was in high school.

I’m wanting to stay the night with my boyfriend in a few weeks when I graduate college. I’m terrified to ask my parents even though I know I don’t have to ask cuz I’m 20 but out of respect to them and because they like to know I’m safe. I’ve never stayed the night at a guys house and I just started dating him but he is willing to wait for me to be done with class. So then he wont be a distraction. I need help on how to talk to my parents about this. About me being an adult in an adult relationship.