Last Ex to Brooklyn

S6, E2: When Leo (Harry Connick, Jr.) invites his hip and trendy ex-girlfriend (Oscar winning guest star Mira Sorvino "Mighty Aphrodite") to a friendly dinner party, Grace (Debra Messing) turns to Will (Eric McCormack), Jack (Sean Hayes) and Karen (Megan Mullally) to round out the guest list and keep the night running smoothly. However, when Leo's ex turns out to be the only girl Will ever slept with, Grace's jealousy gets the better of her. Meanwhile, Karen discovers Lorraine's dog Chompers hiding in Stan's closet and searches for a new owner for the puppy.