For four months Matt Damon and Greg Kinnear shared a body built for two—thanks to a harness they wore up to 12 hours a day—during filming of Stuck on You, the new Farrelly Brothers comedy in which they play conjoined twins who become celebrities. Naturally they insisted on a joint interview.

•Did you guys know each other before doing this film?

DAMON: We'd met at a couple of events and lied and told each other we really liked each other's work.

KINNEAR: The next time we met, it was to go into a room...

DAMON:...and take our clothes off...

KINNEAR:...and get harnessed together and get the feel of what it was going to be like for the next four months.

•That sounds pretty intimate.

DAMON: It was an accelerated courtship.

KINNEAR: No drink, no dinner. It was straight to the stuff.

•You even had to go to the bathroom together?

DAMON: For guys it's a lot easier, because we grow up going into urinals. So you're used to having guys around you. You're just not used to them rubbing up against you and...

KINNEAR:...and blowing in your ear, which I would do on occasion.

DAMON: Greg said it was like going to the bathroom at the end of a Springsteen concert...

KINNEAR:...when there's only one working urinal in the whole stadium.

•If you were women, you'd have told each other all your secrets.

DAMON: There weren't many secrets by the end of four months.

KINNEAR: It will all be in my book about Matt.

•Would you trip each other as you walked in that thing?

•KINNEAR: No! Any act of violence against the other is an act against yourself. We were very kind to each other.... If you're going to do a conjoined twin film, I would recommend being attached to Matt Damon as much as anybody. Except Halle Berry.