Completely embarrassed 😩

So today while we were watching tv in the living room, my 5yr old son told us how he say my husbands “pee pee” on my face one night when my husband and I were in bed 🤦🏻‍♀️ has anyone else had to deal with their child “walking in”? He told us he was peeping through the door 😩 I’m mortified and totally scared he will mention it at a horrible time. Idk what to do or how to address it or if I should ignore it and hope he forgets what he saw. I was SOOOO embarrassed! My husband and I only partake in such late at night when the kids are already asleep and our door is closed. So idk when this actually happened. But it hasn’t been anytime in the last 2-3 weeks. Advice, anyone? Help.