hi look your having some kind of problem so try this an std/gum clinic i'm not saying you have an std but the staff are really helpful perhaps they can diagnose your problem best than over the internet. they can test you and from that work out what your problem is. it is an odd one. if it was just after sex and no other time then i would say your a sexual miss match this is when your sperm and her mucus react giving you your problem may sound odd but happens. ok hope it helps. good luck
small red bumps on penis forskin after and head also pink irritation on base. happens after masterbating or intercourse. first thought it was contact dermatitis with my gf but it becomes irritated after masterbating too. it's very mild and not that noticeable unless you know it's there. when we were not using protection and had frequent intercourse it would become more severe and would flake the day after. could this be a yeast infection or some kind of bacteria?