It would be too easy, but not altogether inaccurate, to describe Sean Saves the World (Thursday, 8 p.m., NBC/Ch. 5) like this:Imagine Jack (Sean Hayes) from "Will & Grace" was (briefly) married, has a teenage daughter, has an overbearing mother and works for a very odd man. And the resulting sitcom is seriously lacking in laughs.That, unfortunately, is pretty much the case.Hayes stars as Sean, a gay man whose 14-year-old daughter, Ellie (Samantha Isler), has spent her life spending weekends with him. But her (unseen) mother has just moved to New York, and Ellie has moved in with her dad.And Sean's smothering mother, Lorna (Linda Lavin, "Alice"), doesn't think her son is up to parenting her granddaughter.In the second episode, Megan Hilty ("Smash"), joins the cast as Sean's best friend, who fights a lot with Lorna.And, like "Will & Grace" at its worst, "Sean Saves the World" confuses tasteless and vulgar with funny. In one episode, Lorna encourages her granddaughter to examine her own vagina in a mirror. Another episode is replete with uncomfortable incest jokes involving Lorna and Sean.It's gross and creepy.And it's filled with slapstick the likes of which we haven't seen much since "I Love Lucy."There are occasional laughs here, but "Sean Saves the World" is mostly loud and, well, sitcommy. None of it seems even vaguely real - it looks like actors on a soundstage saying weak lines in front of a hyped-up studio audience.Not that there's anything wrong with traditional sitcoms. But the good ones make you forget it's actors on a soundstage for half an hour."Sean Saves the World" just wastes a half hour of your life you'll never get back.