Just want to see some original ones people have used in the past. Here's two of mine I can think of...
Worked:
You've been a bad, bad girl. Go to my room!
Should have worked:
Hey, Jenny! *big hug* I haven't seen you in FOREVER! *huge kiss* Wow, you've really changed! (She says: I'm not Laura) Whaa? Oh my god, you even changed your name!