Daughter wants to sleepover with her boyfriend at his house or our house

My daughter is 15 and has been asking for the last two weeks about a sleepover with her boyfriend I know his parents very well have since before they started dating they have been dating for four months.

His parent sand myself are very iffy about it we know and trust them both but we don’t want them to move to fast

Edited——

I’ve asked her why and she had said I don’t care about having sex I just wanna know what it’s like to be cuddled and wake up beside someone you love

Edited

My daughters room is across from mine and she always sleeps with the door open