While you are first inserting your penis during missionary sex, look surprised and whisper in a whiny McLovin voice: "Its in... Oh my god its in!" As if it was your first time.
Chick: I want you so bad
Dude: Its in... Oh my god its in!
Chick: What the fuck?!?!
Chick: Is this your first time?!?!
Dude, I gave this chick The McLovin last night, she was so pissed.