my boyfriend and i had been having sex (unprotected and protected) for about 5 months. all of a sudden he started getting red itchy and bumpy skin on his lower penis and even peels sometimes. it only happens when we have sex. i got checked for infections and i had nothing. the rash goes away after a few days. i have no idea what it could be. i originally thought i had given him a yeast infection which is why i got tested for it recently. it's not an std. could it just be irritation?