I’m 19 years old, male, and I have experienced sex for the first time. I did it with the girl next door. We live in the same apartment building. We have been having sex for the fourth time already and I’ve been using condom every time we have sex. During that 4th time, even with condom on, I got this skin irritation on my penis during sex. Not the whole penis, (how do you call this part?) it’s on the base of the penis, the area on which the condom can’t cover. It’s itchy. So right after sex I took a shower and cleaned the affected part by soap & water. It has been one week after that encounter, and I still have the irritation. I don’t know what to do. What might have caused this skin irritation? Where did I get it? Is it because of the friction between my penis and her vagina? Do you consider this as an STD? Does this mean that my sex partner has an STD? I really don’t have any idea. What should I do? Please advise. Thanks.