So I'm dating this guy. And every time we seem to have sex he would get these sores on his penis during and right after. They would mostly be around the head and a few random ones around the neck of his penis. He has a hard time turning me on, so we mostly just use spit as a lubricant. The sores seem to look really dry and kinda flakey. They are gone atleast 4 days after if not a shorter amount of time. What would you suggest this be from