Telling parents about moving in together

Hannah
Hey guys, so my boyfriend and I (bith of us are 20) have been together for almost 6 years and he finally got accepted to a college near mine. He needs a place to live, and it makes sense for him to move in with me. Our rent is going up so my roommates and I are going to be paying over $600 each but if he moves in we are paying less than $400 each. However, my dad doesn't know that we have slept together (even though it seems really obvious) and he's paying my rent kind of (he matches the amount I get in scholarship money so I can pay rent and food and such). I'm scared he will get upset with me. Any advice from anyone who has been in that boat?