"French In Scotland" joke

One cold December day, a French tourist in Scotland decided to find out if the natives were as tight as he had heard.
He stopped at a farm cottage, told the farmer's wife he was freezing to death, and was invited to come in and warm himself at the hearth.
Once inside the house, he complained of being thirsty.
The woman handed him an enormous white crockery mug filled with milk.
After taking a big swig, the impulsive guest exclaimed, "This is sweet and fresh... you are most generous!"
She replied modestly, "It's nothing. My family wouldn't drink that milk
because we found a dead rat in it."
Sick to his stomach, the Frenchman clapped both hands over his mouth,
allowing the huge mug to fall to the floor and shatter on the stone.
The Scotswoman grabbed her broom, raised it high in the air, brought it
down on the visitor's head, and hollered, "Get out, you ungrateful pig!
I take you in my home, I let you share my fire, I give you milk to drink... and now you repay my kindness by breaking the children's potty!"