I have had a sort of similar problem! (as the original post) I am the same age, if my maths is working, (27) but my boyfriend's age is very different to yours. I was with a guy for a couple of years who was 34, and he would 'hold back' on his cllmax often whilst I would just have multiple after multiple, every time we had sex, which was about 8 times a week, often more. (he did this purposefully, to conserve what traditional chinese medicine calls jing, but there are lots of diffferent names for it) This is a pretty high rate, I realise, so while I did worry about me having all the fun, I also thought it was ok, as I also noticed that the more he actually did ejaculate, his libido would be lower next time. (that sounds so awfully selfish, I'll apologise now) He would always assure me that despite not coming, he loved to pleasure me, loved to see me cllmax, and was having a great time etc, so I really didn't worry. I also thought 'he is a little bit older, of course he won't cllmax every single time'
Since we broke up (about when we realised that the great sex was actually all that we had in common) I now have a new boyfriend who is just 23 so he should be different right? I read and read and read about women who are frustrated with men who come too quickly, but I haven't ever met one... I always get the ones who take ages and ages... On top of that, I have a very high libido, and cllmax very easily. I never seem to meet the ones who can keep up with me! In answer to the original question, I would say, if he says he is happy, then he probably is. And, never underestimate how much men are turned on by turning YOU on. They love to see you turn into a helpless puddle of cllmaxic inebriation, all done by their big tough manly selves.
I say have fun with your man, and believe him when he says he is happy and loves you.