boyfriend sleepover

I sleepover at my boyfriend’s house frequently and I want him to stay over at my house. He has once, and he stayed in the guest room because my parents don’t like the idea of him staying over. My mom claims she is against it for religious purposes... since God is against sex before marriage. my dad.. idek what his deal is because he is barely religious.

help me figure out how to convince them:

-my bf and i are both 18

-we don’t have to sleep in the same bed (which fucking sucks)

- my parents love my bf and he is very respectful and polite

lmk cuz this is stupid