You have told your 18 year old that he has to be home by 2:00am.
He's a high school graduate.
He doesn't have a plan yet.
You have told this man child on MORE THAN ONE OCCASION TO NOT COME IN YOUR HOME PAST 2:00AM.
It's past 2:00am. He's not home. You put the deadbolt on. He comes home at 3:15am. It's 20 degrees outside. He doesn't have a car.
Do you let him in?