My DP tells me that his view is our DCs, both almost 18, can only have their partners over to sleep the night, if they have been in that relationship for at least 6 months; or that they already live together (ie coming back to ours for a visit).
My view is, this is their home, I trust their judgement (they are both great kids) and if they chose to have a partner over for the night that's fine. I'd be a bit WTF if it was a one-night-stand, but not someone I know they have feelings for.
It isn't the sex he's objecting to, he's okay about them having a sex life, it's the sleeping over.
AIBU to argue about this with him, or is his view more usual than I think?