this is probably just skin irritation. use a penis health creme called man1 man oil. it is made just for issues like this and will not only treat you current problem but make sure it doesn't happen again in the future. it is a great product that tons of guys use nowadays. hope this helps.
small red whelp like bumps and red dots appear on penis after unpretected sex and the next intercourse it itches? . in a relationship with the same girl for over a year now. first 6 to 8 months never used a condom as she is on bc and never had a single issue but the last 3 months every time we have unprotected sex my penis gets irritated with red whelps and bumps. then the next sessions it feels like i am scratching an itch and i climax quickly. days after it will dry up and disappear. tried using a condom for a month and when we stopped it happened again. she has absolutely no symptoms or signs at all.