People should really learn what the point of that knot is for! In simple terms it’s to stop the dog from pulling out it inflates insider her (I don’t know if the female also clamps down on it too.) locking the two together until nature has decided that the job has been done and the male as thoroughly emptied his load into her and that she has taken the seed in impregnating her, it takes about 5 to 10 minutes before the knot goes down and the male can finally pull out and run off.