Sorvino adds an ex factor to ‘Grace’

The geometry of jealousy and lust, in its classic form, is the love triangle. Tonight’s “Will & Grace” involves what can best be described as a love pentagon.

Forming one of its sides is guest star Mira Sorvino, who plays the alcoholic ex-girlfriend of Grace’s husband, Leo, portrayed by semi-regular star Harry Connick Jr. They’re joined by series mainstays Grace (recent Emmy-winner Debra Messing), Will (Eric McCormack) and Karen (Megan Mullally) in the web of desire. (You were expecting Donald H. Rumsfeld?)

As is standard operating procedure for sitcom-land, Leo and Grace are hosts of a meet-the-ex dinner, and Grace has invited pals Will, Karen and Jack (Sean Hayes) over for moral support. Rather than lending her some backbone, though, they turn Grace into emotional Jell-O.

Without giving too much away, the crux of tonight’s episode (on NBC at 9:30) is that Leo’s ex is also Will’s ex -- a bit of a surprise, considering that the latter man is gay -- and that Grace is more upset over the Will revelation. This leads to a slew of one-liners and double entendres whose quantity far exceeds their quality.

If all of this seems a rather insignificant trifle, it is. But given that “Will & Grace” is in its sixth season and still a top-ranked show, that’s apparently what the public wants. And heck, it won four Emmys last month.

As for Sorvino, you have to wonder if this role is what she had in mind when she won an Oscar as best supporting actress for 1995’s “Mighty Aphrodite.” Then again, maybe it’s better not to know. Don’t ask, don’t tell.