Fans of TLC's Jon and Kate Plus 8 know Kate Gosselin can be a strict mother.

But a newly surfaced video shows just how stern she can really be.

In shocking footage (posted on YouTube Thursday -- the day before she and Jon celebrate their 10th wedding anniversary), Kate sits with her eight kids as they prepare to do a television interview.

The kids complain they're thirsty.

"I want a drink!" Mady yells. "I haven't had a drink all day."

See what Kate Gosselin looked like in high school

Kate ignores her.

"Mom, I'm going to get dehydrated!" Mady goes on.

Kate dismisses her: "Yes, me too."

See what Kate Gosselin -- and other stars -- look like in a bikini

Kate then orders a bottle of water. But instead of offering her daughter a sip, the mom of 8 takes a quick chug.

"I need a drink now!" Mady pleads.

Kate tells her to "be quiet," prompting Mady to cry, "You're really, really mean!"