Tell him that you want/need him to cum in or on you, perhaps even begging. If you’re more dominant, you might demand that he cums. You can whisper it in your his ear, too.
Try telling him not to cum. Some guys can’t resist, and this makes them cum fast.
Stimulate his prostate.
Moan, breathe heavily, and show that you’re enjoying things.
Have your own orgasm. Sometimes guys only let themselves cum after their partners have. You can even suggest the two of you cum together if you’re good at controlling your orgasm.
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