After having sex with my girlfriend I noticed that the head of my penis is red and kinda rashy. It's also very itchy. And she has noticed the same thing with her vigina. She said it hurts when she pees and when it gets wet and that's the same for me except it doesn't hurt when I pee. I was first thinking that it's a cause I don't always clean my penis throughly after sex or on a regular basis. But i just don't know at this point. Any help?