She said he was sitting with his class in primary (sharing time, for those who know what that is) and was loudly having a conversation with really no one in particular. This is how it went:
Luke: So, my mom has a little baby in her tummy...want to know how I know?
(No real response from anyone, but he certainly had my friend's attention at this point)
Luke: Because there were two lines on the stick.

(I wonder what other things he's decided to share....)
P.S. Don't worry, this is not my "stick."