Me and my boyfriend had sex today and then after he cum his dick started itching and im scared but I know that I don't have any s im really scared and before after he would cum his dick would burn but I know I don't have anything and neither any symptoms

Well, . Well, there are some sexually transmitted diseases that you might not be symptomatic from. The bottom line is that when you have sexual intercourse with someone without barrier protection you may be putting yourself at risk. I do not know if he was reacting to a lubricant, I do not know why his penis felt itchy. But, if you and your boyfriend do not use protection, you are potentially taking on risks from each person's past sexual partners.