“LUV,” Murray Schisgal’s comic take on that curious geometric entity, the romantic triangle, enjoyed a giddy run of over two years on Broadway in the mid-1960s.

It might have been more effective at sketch length, but instead it stretches a tiny bit of wisdom on the impossibility of sustaining a relationship, let alone a marriage, into an evening’s worth of theater. Schisgal is not above stooping to silliness, which makes the material exceedingly fragile stuff but still amusing light entertainment.

At Manalapan’s Plaza Theatre, director Andrew Rogow either encourages or allows his talented three-member cast to mug its way through the play, which tends to evaporate the comedy. Those unfamiliar with “LUV” may enjoy some of its wryly absurd turns, but those who recall other earlier productions need not apply here.

Schisgal, the social satirist who went on to co-write the movie “Tootsie,” asks us to consider the extremes we go to in the name of love and the speed with which we jump in and out of love.

“Jump” is the operative verb in the play, since it opens on a Manhattan bridge, where unkempt, despondent, unloved Harry Berlin has come to jump to his death. Fortunately for him — maybe — an old schoolmate, the more solvent, seemingly well-adjusted Milt Manville happens along and saves Harry from a briny demise.

He tells Harry that he not only knows love, he is more in love than the day he married. But his wife Ellen refuses to give him a divorce. (Rim shot!) So Milt decides on the spot to introduce Ellen to Harry, even though they are supremely ill-suited for each other.

Naturally, they fall madly in love, at least until intermission. By the second act, Milt’s girlfriend has dumped him, Ellen has grown sick of the infantile Harry. So the formerly married pair meet again on the bridge, embrace each other and embrace the idea of pushing Harry to his death.

If you have ever seen Road Runner cartoons, you have an idea of what ensues.

Along the way, Schisgal injects some enjoyable “can-you-top-this” comic shtick. Early on, Harry and Milt challenge each other on which one had the worse childhood and, later, Harry and Ellen wreak havoc on one another to test the limits of their love.

Following up on its recent success with “Driving Miss Daisy,” the Plaza again draws some of the area’s fine actors to “LUV,” but calibrating the comedy proves difficult. As Milt, Avi Hoffman is a hapless nebbish in ill-fitting clothes, straining for laughs that often do not arrive. Steven J. Carroll’s Harry is exceedingly cartoonish, which he milks in a scene of sensory losses.

Patti Gardner has the most understated assignment as Ellen, a no-nonsense, overeducated realist who for some unknown reason is mixed up with these two losers. Ellen’s view of gender roles and her decision to subvert her intelligence probably dates the play more than anything.

Often out of phase with each other, all three characters profess their belief in love. I believe in “LUV” too, but it probably needs a more deft rendering than it receives at the Plaza to turn others into believers.