Boyfriend Allergic to my Vagina?

I've been with my boyfriend for about 8 months now. We've always had really great sex without any complications. In the end of the summer he voiced that he was experiencing a burning sensation after having sex (when having sex without a condom). If he didn't clean up afterwards he breaks out in a rash and skin starts to peel of his penis. Yesterday after he gave me head his face started to burn (gross, I know, it was all red) and then when we had sex he wore a condom but when I came it burned his stomach area. We both are negative for STD's and all that jazz and it's not baceterial vaginosis or a yeast infection. He does have dermatitis (eczema), which I read can someone's lead someone to be more susceptible to irritation. Has anyone else had this experience? He's the only person that I've had this happens with and he said I've been the only person who has had this experience with as well. Not much is out there on the internet... I've read it could be a multitude of things (change in diet, allergic reaction to a food I ate, etc) Could my boyfriend actually be allergic to my vaginal secreations?! HELP