Please, please do not let him get this procedure.
I had the exact same problem as a teenager - I was never taught how to properly clean and pull the skin back, so my foreskin was unable to stretch and it was painful during sex. I looked online and consulted doctors, and hands down every doctor I talked to immediately suggested circumcision. Every website in the United States that I read suggested circumcision was the only solution. But guess what? That is TOTAL bullshit.
I started doing research with websites outside of the U.S., where circumcision is not as common (primarily the U.K.), and every single one of them mentioned stretching as a very possible solution. Something none of the doctors here in the states even mentioned.
I read more, on the various stretching techniques and methods that these sites suggested, went home and started very slowly. Basically, I would stretch it and hold it for about a minute while I had an erection, and the same after orgasm (with the cum and stretched skin it seemed to help a lot). Once I was able to pull it back far enough when flaccid that it would stretch all the way down the shaft of my penis, I would pull it back to expose the head every time that I used the bathroom. That would mean about 2-5 times per day.
It took me about two months, and, after that, I could have sex without any pain. TWO MONTHS - as opposed to a procedure that would have changed my penis for life? Ridiculous.
Doctors in America are not taught enough about the realities of circumcision. It does not improve a persons health in ANY demonstrable way - unless you live in a culture without access to clean water.
As well, my greatest fear, and one I think your boyfriend should be very aware of - even if you don't think circumcision will change much during sex - it will. Your boyfriend has grown up masturbating and orgasming with an un-circumcised cock - the sensation will be completely different, the cock will be constantly exposed, rubbing against clothing and underwear, and the sensations during sex will be totally unfamiliar and NOT any more pleasurable than they are right now - the un-exposed head of the penis will be extremely sensitive for months after circumcision. By the time it gets used to be exposed constantly, he could have stretched his foreskin enough to have it retract fully during sex.
As well, he will eventually lose that sensitivity with it being constantly exposed, and the head of his cock will dry out quite a lot. He will lose a lot of the sensitivity, and masturbating may actually hurt - AND he may not have the level of sensitivity that he is familiar with so may not be able to achieve orgasm at all.
And finally, worst case scenario - he could get seriously hurt or injured, have the surgery heal wrong, or have any number of disasters occur when someone is cutting one of the most sensitive organs in his body, and he may be unable to achieve erections at all. Or he may even develop psychological blocks related to having a changed penis - one that is totally different, exposed, dry, and less sensitive.
So please, please DO NOT listen to people who tell you that your only option to fix this problem is surgery. It is complete crock. I had this exact problem as extreme as it could possibly be (NEVER pulled back until I was about 18-19 years old) and I fixed it on my own in two months with a dedicated stretching regime.
Link below is a good basic guide (I don't have any of the old sites I did my research on - I am 27 now and have been very happily sexually active so haven't needed them since), but by all means please do research and have your boyfriend read materials from the U.K. medical journals and/or call and talk to doctors over there. The U.K. only circumcises about 5% of their population (primarily jewish residents) so they have tons of information on how to fix this problem without resorting to a long-term, painful, and totally unnecessary surgery.
http://www.healthboards.com/boards/showthread.php?t=178155
This issue is something that is very personal to me, because of how close I came to making a major mistake with my body - and how angry I was when I found out I was almost led to this decision in ignorance of a much simpler solution. Please don't let your boyfriend make this decision without reading all the information out there.