A Chorus Lie

S4, E16: A desperate Jack seeks to "in" his rival (guest star Matt Damon, "Ocean's Eleven") for the last spot in a popular gay men's chorus that will tour Europe by dangling a motivated Grace (Debra Messing) as date-bait before him to prove that he's actually straight. Meanwhile, a scheming Karen (Megan Mullally) tries to pass off an unwitting Will (Eric McCormack) as her lover and not her lawyer when she discovers that she's the object of pity for being single at her own Valentine's Day party.