During anal sex, the man ejacualtes into the anus of the male or female
receiver.
When the receiver later uses the toilet, what comes out of the anus, a mixture of
ejaculate and feces is a poo baby.
Chris and Sean, sitting in a tree,
K-I-S-S-I-N-G,
first comes love, then comes
marriage,
then comes the poo baby in
the toilet carriage.