I'm not sure how to ask my son if he's been molested

My soon to be ex-husband was charged and convicted of molesting our daughter. The police, CPS, and two counselors interviewed our two sons and said they believed neither had been molested. Today out of nowhere my youngest son asked if I wanted him to put lotion on his balls and make his penis pee lotion. That image and recent events make me wonder if he's talking about something no eight year old should know about. Am I just being paranoid or should I be worried? I asked if his father hurt him or touched him in places he shouldn't and he said no but I'm not sure if he's telling the truth or trying to protect his father. I don't know what to do. via /r/Parenting http://ift.tt/29anETL