Penis problem

[rgsBMX021]

Okay, I appear to have small shiny red bumps on my penis and my scrotum. They have been there for a while so it never bothered me, until recently. About a month ago me and my girlfriend were messing around. And after we were done I noticed a red rash that appeared to be like road burn on the head of my penis. This really scared me. It healed up after about a week. Then the next time me and my girlfriend messed around, it happened again. It has stopped doing this, but about a week ago a small bump appeared. It was slightly painful to the touch(like a pimple) but it only hurt for about a half hour.  The next morning it was gone but had left smaller painless bumps in it's place. Also, there are what appear to be purple scratch-like marks on my upper legs around my penis.

I only had unprotected sex a few times. And the last time I did was almost a year ago(with a different woman).

Unfortunetly, I can't post a photo, so if someone could try explaining it based on my description, that would help a lot.

Thanks

[IsNotHere]

I'm not a doctor, but I'd recommend having this checked out by a doctor or dermatologist.