I am 16 years old and about two months ago i had unprotected sex with a girl i knew quite well, and quite sure she didnt have anything. the day after i noticed little red dots/rash like things on the head of my penis. these did not hurt at all, did not itch, did not burn when i urinated, no discharge, no discomfort except for my confidence. after about three days of getting them they were completely gone. a couple days ago i had unprotected sex with my ex girlfriend ( a different woman than before) and got the same red dots/rash. in the time period where i didnt have sex they did not come up at all and my penis was fine. masterbation did not irritate my penis, it was normal, only when i had sex. why im so confused is that my ex girlfriend is now experiencing a little pain and itchyness, also some discharge as she has told me. she also said the sex hurt. the red dots on my head are almost gone. is this something serious?