Usually stay in. If they ask me to pull out I usually can, or sometimes I want to use the jizz for lube somewhere, or maybe lick it up and give a sticky kiss or a snow ball.
No question about it,you gotta stay in and make sure your balls deep when you cum.. There is nothing like cummin in a nice tight hole feeling that sweet pussy,ass or mouth gripping on your cock as you build up and explode...