The Joos are a product of divorce. See, all you families out there? This is what happens to your kids if you get a divorce - they swear, steal, and have indiscriminate sex with strangers. Or at least they swear. And live in the armpit of the Midwest.
Because the Joos come from a broken home, they spent summers and special ski season bonding time with the father of the Joo clan, Father Chris (a.k.a. The Nice Priest who sends Christmas gifts sometimes). As time progressed, Father Chris fathered a son with a brand spankin' new wife, and eventually, that son joined the Joos on their fatherly visits.
On one such occasion, when the Little Half Joo Son was five or so, the Joos were delighted to discover that he could be manipulated with physical force and emotional abuse. The Joos therefore threatened the poor Little Half Joo Son with "BEAT DOWN" every time he whined or displeased them in any way.* This was the source of much hilarity to the Joos, as you Internettes might imagine.
After one particularly long day on the slopes, TLHJS decided to unwind on the walk home by chewing on a ballpoint pen. Perhaps it was the constant beating down, or the fact that his daughters verily had vomited all over God's Green Ski Slopes, but this particular act of LHJS threw Father Chris into a frenzy (Note the clean language used by Father Chris in times of turmoil. He must be so ashamed of his offspring).
The scene: the foothills at Vail. A family is returning to their car after a long day of skiing.
FC: JUDAS PRIEST. For the love of Cripes. LHJS, put that down. Don't eat that.
FC: Because it's poison, for Cripe's sake. You'll die.
LJHS continues to gnaw on end of pen.
FC: GOL DARN IT, NOW, STOP IT. YOU'RE GOING TO DIE
FC forcefully pushes pen out o' the mouth of LJHS.
FC: If you're going to eat that, you might as well just die. It's poison.
LHJS picks the pen up. FC pushes both the pen and LHJS to the ground. LJHS attempts to rise from fallen position in snow. Bad Joo and Good Joo look on from now very far away, pee slowly spreading through the snow around them, so heartily are they laughing at the ridiculous spectacle.
FC: Just lay down. You're dead. You died. You're dead.
And so, Internettes, the Joos can confirm through experience that age-old addage: The family that skis together dies together.
*As used herein, the phrase "BEAT DOWN" shall mean "to hold down and pretend to punch, kick, and mutilate a small child whilst hollering, 'beat down' and cackling gleefully."