6 yr old son touching my privates while I'm asleep

I was recently woken up in the middle of the night to my 6 year old son who sleeps in bed with me, trying to look at my private areas while I was sleeping. I've had talks with him about his privates and made sure he knows that nobody should ever be trying to look or touch them. But I'm not really sure how to address this. Please help. I don't want him to feel like he's in any type of trouble or shame him. But I also need him to know that it's inappropriate. Is this normal for his age? He also has ADHD.