I suffered from this exact same problem when I was younger, and looked into how I could work to fix it. Every doctor I spoke to and every page I found from the U.S. said partial or full circumcision was the ONLY solution.

Then I started reading medical websites based out of the U.K. and Europe, and guess what? Turns out it can be fixed with simple stretching. What would have been a dangerous, expensive, and LIFE-CHANGING (in SO many ways) procedure was fixable with fucking stretching? And NONE of the U.S. doctors even mentioned it to me as a teenage boy?

I was (and clearly still am a bit) pissed about that. Suffice it to say, I stretched it casually for about three months and was able to full retract it even with an erection.

My suggestion to him is to stretch it more (it should retract at least partially when erect). It will be SUPER sensitive for awhile when it is fully exposed during sex, but he will soon adjust to that new level of sensitivity.

To respond to your first concern (his difficulty with orgasming) I would say that in my experience the foreskin tightness is NOT the reason for difficulty with orgasming. When I was younger and it was so tight I could not pull it back at all, it was hard to orgasm because it was painful. If it is not painful for him, then there shouldn't be any interference with his sexual gratification. The body adjusts to the sensations it is given - meaning that as long as he isn't experiencing pain and he normally orgasms from a covered head then the issue isn't the foreskin.

One of the reasons that men who are circumcised don't know about stretching is because we are raised to be a bit shy and embarrassed about it (which, thank god, is changing because circumcision is fucking horrible so fewer and fewer people are doing). But part of being shy sexually through our formative years can be that we spend a lot of time masturbating and not as much time getting laid (especially if its painful the first few times we try) and so we develop death grip:

http://www.thestranger.com/seattle/SavageLove?oid=14968

I would suggest:

1) stretch it a bit more so he can retract it partially during sex.

2) look into death grip issues and see if that will help his ability to orgasm with you.

3) you educate yourself on circumcision and come to really appreciate how wonderful it is that he has a foreskin (not that you don't now, but the more educated and understanding you are the more comfortable he will feel). Read this to understand how lucky your boyfriend is:

http://www.nocircpa.org/4642.html