squirting problems

Okay I feel a little weird saying this but when me and my boyfriend have sex it's amazing and I can feel myself about to squirt I have before once or twice but only when playing with myself never while having sex and he wants me to so bad but I don't I feel it coming and I just hold it in or make him stop into I feel it going away I just don't want to have a big mess to clean up afterwards plus I'm afraid that if I don't he will be disappointed tell what should I do