Forget Tony Dovolani's brave face and chirpy public support of Dancing with the Stars partner Kate Gosselin.

Behind the scenes, "he can't wait to get rid of her, even if it means losing early," a show insider says in the new issue of Us Weekly, out now.

Last week's fiery clip of the the duo struggling to rehearse and get along (Dovolani threatened to quit) is only the tip of the iceberg, multiple sources say.

According to one, the "argumentative" reality mom, 35, snapped at Dovolani, 36, during a particularly frustrating practice at her Pennsylvania home: "I'm the reason anyone knows your name," she spat, "so give me a break!"

Gosselin has even commanded that Dovolani enter her house through the basement door, rather than the front entrance. "She says it's quicker, but she's just showing him she's the boss," a Gosselin source says.

"They hate each other," a DWTS insider says. "Backstage, she will back him into a wall to talk, and he won't listen or look at her."

Dovolani hasn't kept quiet about the friction, either. The dancer "complains to producers about how impossible she is. He doesn't want to be around her unless he has to," a source recounts.

Adds another, "Not only is Kate the worst dancer, but she's nasty. It's an ongoing joke how Tony got the short end of the stick when he was assigned to Kate."

To read more about Kate's latest drama -- the pro partner she'd prefer, why she resents Nicole Scherzinger, how she calculated her kids' Easter egg hunt to "one-up" ex Jon and more -- pick up the new issue of Us Weekly, on newsstands now.