He needs to concentrate on something else when he realizes that he is moving along too quickly. maybe he can think about baseball rbi's or something.
There is also a product available that numbs that area so it will take him longer to enjoy the feeling. Once he has mastered techniques to help him enjoy the pleasure he will want to take it slower
Try different positions. Some guys are known to have extremely sensitive sexual parts and the only thing you can really do as his wife is find a position that decreases his stimulation. If you experiment enough with him you'll find a way to maximize your enjoyment and keep him from the brink of climax long enough to have a great session with each other. I know this answer is a little bland but I don't want to get too specific on here. I hope this helps.