A girlfriend and boyfriend walk into the girlfriend's house and the girlfriend said to her mom, "Mom, my boyfriend and I are going up to my room." "Okay honey, you kids have fun," says the mom. When they're up there, the mom hears, "Baby, baby, baby, oh!" The mom walks to the the door and asks, "What the hell is going on?" The girl says, "Mom we're having sex." The mom says, "Oh, thank gosh, I thought you guys were listening to Justin Beiber."