J.LO'S TURN: Even the jaded fashion crowd was impressed when Jennifer Lopez showed up at the Marchesa presentation on Wednesday. The very pregnant star (who's due in the next few weeks) got a tour of the collection at the Chelsea Art Museum from the Marchesa designers, Keren Craig and Georgina Chapman. "I like the very big ones," joked Lopez, wearing a blue knee-length Notte by Marchesa frock as she took it all in.

Meanwhile, her husband, Marc Anthony, told Craig about domestic life. "I can't complain about anything in the house anymore. But I'll be there to support. I don't know about the squeezing stuff, but I'll be there."

As for Lopez's teeteringly high spike heels, "that's professional," said an impressed Joy Bryant.

K-FED'S VISIT: Marc Jacobs is well-known for his surprising — and controversial — front-row guests: remember Winona Ryder post-shoplifting scandal, Lil' Kim fresh out of jail and Michelle Rodriguez wearing her alcohol monitoring bracelet, anyone?

This season is no exception, as Jacobs has invited Kevin Federline to attend. But Federline, who's in town for meetings about a possible acting gig and who also will attend the Sean John show, will have to trade in his signature wifebeaters and white kicks. Jacobs is dressing Federline from his men's line for the occasion. And any concerned Britney Spears watchers need not fear: Federline is only in town for the day, so he won't be separated from their two sons for long.

Meanwhile, Jacobs has tapped M.I.A. for his post-show bash at 24 Fifth Avenue. The Sri Lankan rapper won't be performing her own tunes, though: She's slated to be DJing for the night.

TOMMY PRESHOW: Tommy Hilfiger is bringing culture back — bringing fashion week to Lincoln Center tonight by transforming Avery Fisher Hall's Grand Promenade into a runway. According to the American design house, this is the first time a designer has taken center stage at Lincoln Center since Geoffrey Beene in the Nineties — or Bill Blass in the Sixties, for the next most recent. After sitting together at Sari Gueron over the weekend, Maggie Gyllenhaal and Julianne Moore are both again expected at today's show. Moore visited the new Tommy Hilfiger women's boutique on Bleecker Street to chose an outfit for the occasion, while Ioan Gruffudd, from the "Fantastic Four" movies, shopped at the Tommy Hilfiger SoHo store Thursday to find something fitting.