Has he tried thrusting slower to drag out the stimulation as well as switching up positions to buy some time between them? That should give you at least a little more fuck-time.

I can generally last as long as I want to, and it's quite rare that I feel the need to blow before she wants me to. I do like to get off after about 30-45 minutes either way though. Otherwise you get all cramped and it's not really enjoyable anymore. The other thing too is that I have a tendency to get a charliehorse in my leg after going for too long. I've yet to figure out exactly why that is. Probably just a certain position.