Aaaaaargh

Five minutes ago I was in the bedroom rating grant proposals, and I hear Joseph say to Sam in his wee little piping voice: "Put your sperm on me!" Clearly, I could not have heard what I thought that I heard, so I slip over to the doorway, and I hear it again: "Sam, you have to put your sperm on my eggs!" I peek around the corner, and see that both kids are huddled under the covers doing I have no idea what. I ask them what they are doing and Joseph tells me that they are both chickens and they are fertilizing the eggs so that they can have baby chicks. Both of them seem to be fully clothed and not actually making any kind of bodily contact. It would appear that this was a purely innocent re-enactment of the chicken life cycle depicted in one of their books. I am rarely at a loss for words, but I have no idea how to react to this. It did not violate the family rules about nudity, obscenity or keeping one's privates to oneself. It just skeeved me out. Aaaaaarggh!