All sorts of inappropriate

I live at a church. Not actually in the church ('cause that would be odd), but in the house on the church property. I've only lived here for a few months, but at least once or twice a week so far I see a car parked in the church parking lot at night with people making out in it. Sometimes it's even no-holds barred nudity. Usually I see this at night while I'm out walking the dog with my hubby, and Chris has made a point to now go up and knock on the car windows and ask the people inside that if they're not here to pray they will have to vacate the premises.
I just find it hard to wrap my brain around the fact that people think it would be okay to behave this way in the parking lot of a church. I mean . . . a church? Is that not just completely disrespectful? Where's the rationale behind that? It's just all sorts of inappropriate . . .