So When David Lauren Marries Lauren Bush, Her Name Becomes …

At the after party following last night’s New York Public Library Lions Benefit, David Lauren and his girlfriend Lauren Bush, one of the evening’s co-chairs, were inseparable, an eyewitness told the Daily Transom. “He was leading her around all night,” the source said of the handsome clothing scion’s modus operandi at the post-dinner dance sesh on the library’s lower level, where things reportedly got a little raucous.

On top of the sounds of hip DJs Andrew Andrew and constantly-shattering glasses, co-host Amanda Hearst, who arrived with Luigi Tadini, got jiggy on the dance floor. Actress Leelee Sobiesky also appeared to be having a good time last night, though she apparently looked more than a little awkward alongside her companion. While the younger crowd dirty-danced, older partygoers snuck downstairs to peek at the mayhem, often fleeing instantly at the sight of the happy revelers imbibing and making use of a photo booth that was rented for the affair.

After the Young Lions after party wound down around midnight, a chunk of the merrymakers—including publicity stuntmen Paul Johnson-Calderon and Kristian Laliberte, who reportedly looked like the best of friends—headed over to Paul Sevigny’s Beatrice Inn, where the party continued until around 3:30 a.m. (The boozy after-after-party did not, however, involve co-host Nicholas T. Brown, a student at Harvard who had to board a Cambridge-bound bus after the event.)

The annual benefit has always drawn an impressive crowd to the historic façade in Bryant Park, and this year was no different. Among the guests at the dinner, which honored Martin Scorsese, Tom Stoppard, Jhumpa Lahiri and John Hope Franklin, were: Robert Duvall, Philip Seymour Hoffman, Jimmy Fallon, Diane von Furstenberg, Carolina Herrera, Michael Bloomberg, David Remnick, Christine Baranski and Elie Wiesel. Other co-chars in attendance included: Oscar and Annette de la Renta, Christine and Stephen Schwartzman and Hudson Morgan.