It's a battle of the blondes!

On this Friday's all-new episode of Lifetime's drama-packed reality series, The Mother/Daughter Experiment: Celebrity Edition, Kim Richards unleashes her signature short fuse on Heidi Montag -- and only ETonline has your exclusive sneak peek at the tense moment!

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After Heidi asks Kim to be more punctual to the group therapy sessions, the former Real Housewives of Beverly Hills star is outraged, so Kim decides to call out Heidi -- aka that "sweet little Barbie doll" -- for trying to stir up drama in the house.

"Hey, Heidi, I just wanted to say, sweetheart, I personally didn’t like what you just did to me in that room by coming to me," Kim says to The Hills star while all the other women watch with bated breath.

Press play on our exclusive first look above to watch the heated confrontation and catch The Mother/Daughter Experiment: Celebrity Edition Fridays at 11 p.m. ET/PT on Lifetime!

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