My wife gives the best head I have ever had. She's so damn good I never want to leave the house. However... I'm rather large, and it takes an effort to keep her jaw in that position for any amount of time. The problem is that every once in a while she scrapes my frenulum, and, man, it hurts! I mean it hurts for days. I usually don't feel it until long after orgasm, but any subsequent erection or excessive handling makes me withdraw in pain. Any ideas how to either make it heal faster or build up a tolerance? Don't even mention the condom route, she's allergic to latex. Not looking for sympathy, just ideas.