hollywood beanie dancing with the stars hope solo Maksim Chmerkovskiy

Yesterday we spotted Maksim Chmerkovskiy and Hope Solo leaving rehearsals for Dancing with the Stars, and we also caught Nancy Grace, Rob Kardashian and Cheryl Burke sweating it out.

So what's this we hear about Maks and fellow pro Derek Hough feuding behind the scenes? "They hate each other," an insider tells Us Weekly. The boys reportedly squabbled after Chmerkovskiy told DWTS judge Len Goodman to retire the other day, and Derek (who's won the competition three times now) told the mag, "I had a laugh about that [remark] ... I was looking at the plaque upstairs and…well, never mind." Burn!

"The professional dance community is really small. The dancers have known one another their entire lives," the source added. "Now that the group is famous, it's added a whole other level of rivalry and competitiveness."