My boyfriend is 21 and uncircumcised. He says his foreskin has never retracted before and that it stings if it's pulled back too far. I was curious about this and looked it up on the internet and found multiple responses (some guys don't retract; it's phimosis; etc.). So what do you think? I don't really think it's in my place to tell him that he may have a bit of a problem if it's not normal so I am unsure of what to do.

I suppose a doctor is the best person to ask, but your bf may be too embarrased to acknowlegde that there might be a problem.
I would try to find the right time to talk to your boyfriend about this...it affects you both, particularly when hygiene/infection could be issues.