DS7 went through a phase of adoring all things NASCAR when he was around 3yo. No one else in the family is even slightly interested, but he loved them.
He memorized all the cars, drivers, sponsors, teams, etc. for all the cars on the circuit...including Viagra! One day he asked what that was. My short-but-sweet response: medicine for men.
I'm usually very open about human sexuality, but I just didn't WANT to go THERE! Not at age 3!
I couldn't believe that MY ANSWER satisfied him, but it did. Whew! So I sympathize with you. Better you than me, friend!