i need help

[knd12587]

My boyfriend and i have been together for over a year now. We have been having sex and oral sex for a long time, but just recently things started to happen. The past three times he has given me oral sex he has broken out with a rash on his face near the hair on his chin and on near the hair on his lip. We have both been tested we have no STD's. I haven't been with anyone else and i just can't figure out what is going on. What could be causing him to breakout and how can i stop it?