Promoting this week’s Drillbit Taylor on The Tonight Show last night, Leslie Mann showcased her very dry, tongue-in-cheek sense of humor in a quasi-performance piece trainwreck that totally didn’t play, at least with Jay Leno’s captive audience. After confessing that she and husband Judd Apatow don’t sleep in the same bed, because he’s a big-time snorer, Mann talked about instead sleeping with their youngest child, whom she sometimes forgets to properly diaper. “I wake up covered in pee, but at least that’s better than the snoring,” she said.

Met with polite titters, Mann then proffered: “I feel bad… we’re not gay or anything — not one of those couples who pretend to be a couple.” More uncomfortable laughs and even a gasp or two, with surely plenty of folks not making the necessary leap in logic. No matter the smoothness of delivery, this chop-busting humor — the same sort of stuff Michelle Obama got dogged on for dropping on her husband Barack — requires that it comes from a known, vetted commodity, i.e., someone of a similar public stature. Mann doesn’t have that. Yet. So her run-downs of Apatow and other wide-eyed biographical confessions (about how she believes in ghosts, and once dated a homeless man), whether true or not, don’t play. I’m sure she’s been on The Tonight Show before, but she’s clearly still in “introductory mode” with mainstream audiences. Except that someone forgot to tell her…