A farmer decides its time to tell his son how he breeds the animals.
He explains about the cows and the bull, the mares and the stallion and the ewes and the ram.
But he also decides to tell his boy about their one lame pig.
‘Unfortunately she can’t walk far, so when she’s in heat I put her in the wheelbarrow and cart her down to my friend’s farm for some alone time with his boar’.
A few weeks go by, and the boy is looking out the window.
He says ‘dad, the pig is in heat’
The farmer peeps over his newspaper to look at his boy and says
‘how can you possibly know that from just looking out the window’