Lets think of a situation, stormdragon is a young girl (not too hard to imagine) and mattj is her boyfriend.

Storm - I dont want to do _______ with you
mattj - Please?
storm - no, dont come near me, I already told you i dont want to.
*matt grabs/approaches storm anyway
*storm punches matt in the head.

Those are the two points id say you could strike another person in a rapeish type of case. Anytime before that and it would be hard to prove that it was in sd, but if its neccesary, then do it. I think the court would be able to tell that the 15 year old girl didnt hammer her 16 year old boyfriend for no reason.
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"They say the only way to kill a lion is with a rear naked choke, but I'd just kick it in the head"