If they guy is very visual I will have him do his first pump or two and an air shot in to my mouth or on to my face but then immediately take his shaft full length and then get back to full stroke sucking to get the rest of the orgasm out of him. Far too many back off as soon as the feeder shoots. Women are notorious for this. Be aggressive, keep up the suction and tongue work until he begs you to stop. That keeps them cumming back.