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MAKSIM & KARINA - REUNITED ON BROADWAY!

Before they signed on to appear together in Broadway's Forever Tango, Maksim Chmerkovskiy and Karina Smirnoff needed some convincing. After all, the Dancing with the Stars pros' nine-month engagement ended in a vicious breakup back in 2009 - one so contentious that Smirnoff reportedly sat out the 10th season of the show to avoid her ex. "We'd completely erased each other," Chmerkovskiy, 33, admits, sitting next to Smirnoff, 35, in the empty Walter Kerr Theatre. But performing together again "is therapeutic for both of us," says Smirnoff. The pair told PEOPLE about their rocky road back to friendship.

You guys hated each other. How did you become friendly again?

MAKSIM: It was just a month ago. When we broke up, it was like, "Bam!" That was it. We hadn't said a word to each other since. Actually, one word—it just wasn't a very nice one.

KARINA: More like two words.

What was your first meeting like?

KARINA: We had a treaty session.

MAKSIM: She showed up drunk at my house... [Laughs]

KARINA: No! I only had two sips. I knew if we could work in peace and harmony, the show would be incredible, but we have a colorful past. I didn't know if we could do it.

MAKSIM: I don't know about colorful; I think the word is turbulent.

KARINA: See! You go for the negative explanation. I prefer positivity.

You still bicker like a couple. How are you getting along?

KARINA: Working together has been amazing. Much more interesting and life-changing than I thought.

MAKSIM: We connected in a way that we never have before.

KARINA: We know each other on an intimate level. That makes it difficult but also special. The past is the past. Now, we concentrate on the good memories.