ASD

From Ladder Wiki

The Anti-Slut Defense. This is the last minute resistance a woman brings up before she is willing to go to bed with a guy. This can be bypassed by: - Bringing it up first - Agreeing in speach, but continuing the escalation - Taking two steps back till she's ready

Disclaimer: This is not an excuse to force yourself upon a girl. If she says 'No' more then once or twice in a weak, spellbound voice, then you better stop.