My 2 boys were at it for a month before they were fixed. Neither was fussy as to who was the giver and who was the taker. I was more concerned about love juice on the duvet as I was woken up in the night to the two of them humping. It stopped immediately after the chop. I was more concerned about how it could lead to non play fighting (they would have the scruff of the neck in the mouth while the bottom would bounce), and also of spraying.