boyfriend tested negative but gets buttoms on penis

[anonymousisus]

good day! I have been having unprotected sex with my boyfriends. We have been dating for two years.  He is a pilot, so he gets regular yearly medical testing.  Once in awhile, the day after having sex he gets bruises and buttons on his penis. the bruises go within days but the buttons or pimples remain until a week or two then it goes away. it looks clear. he says it does not itch or burn. but it hurts.  this only happens when we have aggressive sex.  He does not get any bruises or buttons when we don't have sex. This also does not happen every time we have sex. we also do not have sex very often.  once a week or once every two weeks whenever our schedules allow us to spend quality time together.  He was tested twice in the two years by the airline professional medical team.  His results for std's is negative.  So he is not infected with any std's.  I have been recovering from pneumonia so my immune system is not so good.  which means if i had anything herpes i would be the first person to breakout.  I too have been tested and I have no std's.  I am confused.  He said I am the first gf he been with and this is happening. It never happened with his gf's in the past.

Can I please get some advise on what is causing this reaction to him.  It only happens during rough sex.  And if his tests comes back negative what's the reason for the bruises and buttons.