Human beings have evolved quite a bit, and are no longer those hairy hunters living in caves. Through this process we seem to have lost some very basic animalistic instincts like hunting skills and basic survival, but haven't lost others, just as impotent. One of them is to never ask a woman her age. It starts at around 16 and only gets worst from there.
It's Mummy num.2's birthday (Noam's mum) and with it comes the usual minefield. It's even harder with tricky song verses.