sometomes but only after i masterbate i get a sore right under the tip of my penis, does that mean i have an std or am i just rubbing it the wrong way?
Depending on whether you've had contact with another, or just exactly HOW you are masturbating, you are most likely irritating the spot so that it is swelling due to the irritation. Have you considered switching hands, or how about your lube? What lubrication (if any) are you using?