My boyfriend have been having unprotected sex for a month now. As far as we both know, we've only been sleeping with each other and both have no STDs. One night, I notice I wasn't lubricated enough - so he used his spit. Well he ended up saying his penis was sore, the next morning. We assumed it was because of all the friction but it has been almost a week and its a red, slightly painful, single lump, under his penis head. I'm also on the IUD and he did mention when he goes hard he can feel it rubbing/scratching him, he is large in length and width. So our second guess would be, could the IUD have scrapped him and the fluids from intercourse have mixed together and it got infected? He went to the doctor and the doctor said to wait it out and to "take it easy"... we had sex, again and its still bothering him. This is both new to us and an immediate response would be greatly appreciated.