My son in an awkward position

Hi, I am a 42 year old mother & my husband is a businessman and he stays mostly out due to his business. I have a son who is 18 years old & he recently started his college. I also work as a teacher in a school & I come back around 3-4pm daily. My son is a very studious and a nice human being. One day I came back from school early and I unlocked my house and went to the bedroom. What I saw shocked me for my life. I saw my son in a compromising situation with another guy of same age. I couldn’t believe my eyes and started yelling at both. My son said they are doing a prank on me and I didn’t believe him. I kept crying whole day on this. I tried to have a frank conversation with him as who does he like and he kept saying don’t think wrong but I cant eat or do anything as I cnt forget that scene. Should I go ahead and discuss it with my husband or how do I make him confront that he is not straight.