[She pulls him into a room and locks the door behind them.] I know you're trying to make a good impression with my mom and I love that you're the kind of guy who wants to do that, but my mother is evil, Steve. All my life she's flirted with my boyfriends, criticized me, and drained my dad of his money and his life. She just loves attention. She always needs more and more and if you give her any, she's going to get worse. She's going to make me crazy.
And don't you like having our little home as an escape? You come over and we can just sneak away together and be alone? The last thing we need is my mother barging into our bedroom in her underwear because she's "doing laundry" or something.