bruised and tender penis

I have a new girlfriend, and since i have stopped using a condom with her, the head of my penis gets bruised whenever i have sex ,its been like that for about 2 weeks now.At first I thought it was her pubic hair that was too coarse even though she gets lubricated pretty easy,so then i shaved it off,but I still get bruised and it stings pretty bad.It heals within 2 to 4 days without any scabbing  then i have sex, then it gets sore again.I am not too sure what causes this but about 2 years ago something similar happened with a prior girlfriend I had. The doctor at the time said it was my girfriend's yeast infection that caused it because the yeast needed warmth to to survive and couldnt exist on my penis. I think he gave me antibiotic tablets and an ointment that cleared me up pretty quick.Could this be the same thing? This girlfriend wears a lot of tight jeans and someone told me once that tight jeans  can cause women to get a yeast infection .

[Alan Rockoff, MD]

Yeast infections are uncommon in men.  They show themselves as intense redness with pustules around the edges, which is not what you're describing.  Most likely you just have friction from a lot of sex.  Lubrication and perhaps some rest periods should be sufficient.  If symptoms persist, you might show a doctor.  (Women who have yeast infections have itchy or sore vaginal discharges, by the way.)

Best.

Dr. Rockoff