Do not know what it is
I have recently noticed one acne on my penis. I am not sure what it is. I never had sex with anyone but my girlfriend, and she has no deseases. I tried to squeeze the acne out and put some alcohol to disinfect it, but the acne appears over and over again. It does not get bigger, but I am not sure what it is. What could it be? And can I have sex with it?