Its probably from shaving, that is the most sensitive area ever that you could shave, and I know because I also shave it all, and I get a lot of irritation from it, and if you shave up against the hair, it gives you a much closer shave but also irritates it more and sometime with me it even bleeds, I could understand it stinging, not sure if this has anything to do with your issue, and your boyfriend going down on you I don't think would have anything to do with it, I think its probably from shaving, maybe try not shaving for a little while? (though as the hair grows out I find it can get more irritated and worse when you shave it again, so maybe not) just be sure to always use a fresh blade, and good moisturizing shaving cream. Try not to use fragancy body washes down there, that sometimes isnt good. Some soaps can be irritant.

:idea: the mouth is a pretty dirty place. First of all make sure that your bf washes him mouth out w/ listine. Second, have yeast infection stuff ready, oral sex can get a really nasty one going!