I'm a 22 year old, sexually active man. I discovered a big, eclipsical lump about two inches wide about 1cm on top of the base of my penis. It doesn't have any different color than the rest of my pubic area.
I noticed it pops out after a sexual intercourse. At first, it wasn't big or painful at all. After a week or so, it began to be big and it's painful when I touch it. Just today, (about 10 days from the initial sexual intercourse) it stings every time I move.