Sex problems

My SO isnt circumsized and when we have sex his foreskin gets pulled back far and it hurts him so we end up stopping. I dont want him to be in any pain but its the 3rd time we've had to stop during sex cz its too painful for him.  Can someone please help me! I dont want my man being in any pain during sex, plus im dying to finish.  What can we do to stop this from happeneing?!