NEW YORK - "There's the Mooch," says Ben Falcone brightly as his wife, Melissa McCarthy, enters the room.

It's a term of endearment, a long-used nickname between the two who have been paired in love and comedy since they were aspiring performers at the Groundlings, the Los Angeles improv school. Their long partnership reached a professional crescendo last week with the release of "Tammy," a road trip comedy they wrote together that McCarthy stars in and Falcone directs.

McCarthy and Falcone, who married in 2005 and have two daughters, are incredibly sweet together - riffing easily and warmly complimenting each other - but you wouldn't know their marital harmony from their movies. Their on-screen relationship is far more combustible.

Falcone was the undercover air marshal in McCarthy's breakout, "Bridesmaids," and he played McCarthy's clingy former lover in "The Heat." In "Tammy," she hurls put-downs and ketchup packets at him after Falcone, playing her boss, fires her from a fast food joint.

"Tammy" was born when Falcone woke up one morning, groggy from a dream envisioning McCarthy and her alcoholic grandmother (played by Susan Sarandon) embarking on a journey away from their small Illinois town. After six years of working on it (and buoyed by McCarthy's now considerable box-office clout), their personal little comedy (both are from Illinois) is opening in the heart of summer blockbuster season.

Q: Melissa, you went to college in Ben's hometown, Carbondale, Ill. Did you ever meet there?

Falcone: I knew who she was. She went through a Goth phase.

McCarthy: I didn't know it but he said we were at the same parties together, which I just find the most bizarre thing. It wasn't until 10 years later that we met.

Falcone: After a year of being friends, we started putting it together. She had blue hair and clown makeup.

McCarthy: I prefer to say kabuki white. "Clown" has sort of a negative connotation.

Q: Did you have similar upbringings?

Falcone: She was probably more popular than me.

McCarthy: I don't know about that.

Falcone: I definitely think so. I wasn't, like, unpopular. (McCarthy starts cackling. Ben shifts into character.) "Listen! Listen! I was super popular!" I storm out of the interview and jump through the glass windows.

Q: So you actually met later in Los Angeles?

McCarthy: We met at a Groundlings class. We immediately were improvising with each other and immediately gravitating toward each other, writing-wise. The first day, everybody's doing their biggest, probably most unrealistic, poorly done characters. And Ben got up there and did this very strange inmate that sat on a chair quietly. I just thought it was the funniest thing. I thought: I like that creepy guy.

Q: Ben, do you remember the first time you saw Melissa perform?

Falcone: It was in that class. ... Her character kept going to the same Kinko's and talking to a guy name Todd. She said the name about forty hundred billion times, like, "Hey Todd. How you doin' Todd? Anyway, Todd, I just need a couple more copies." And it was obvious she was not there for copies at all. She was just there to talk to Todd. It was a super funny and great character - spazzy and fun.

Q: Were you crafting volatile characters from the start?

McCarthy: I love to have a character with a firm belief in their point of view, no matter what it is. It doesn't always have to be aggressive. It can be a really shy person who really wants a cul-de-sac on the end of her block.

Falcone: She steals from everybody. Bits and pieces and then she puts them inside herself. People that she grew up with or relatives.

McCarthy: The fun is, if you can justify it, then it can make sense. I always think in real life, people do so many strange things.

Q: In "Tammy," you throw ketchup packets at your real-life husband.

Falcone: Her suggestion.

McCarthy: You were screaming, "My eyes!" because of those corners, which may have kind of fueled my fire. Which is terrible because in real life, I would never do that. If anything hurt, I would be like, "Oh, my God."

Falcone: I would hope that you'd never be throwing ketchup packets at me in the first place.

Q: Given your success together, these must be good times.

McCarthy: We've been doing it for 20 years for free, with cheaper wigs. We would have kept doing it. If the opportunities that we have now wouldn't have come up, I still think we'd be at the Groundlings doing the same thing: building crazy costumes and crazy sets that do or don't work.