Hanging with (funny) supermodels on the 'How I Met Your Mother' set

You know how people always say that celebrities seem smaller in person, and disappointingly normal? This does not apply to Heidi Klum (pictured, left). Or any other Victoria's Secret model, for that matter. Set your self-esteem lasers to sad, lady readers, because they are, indeed, as lithe of limb, as sparkly of lip, and as shiny of hair as any teenage boy's PG-13 dream. Also, they can be funny. On purpose. I learned all this and more on the Los Angeles set of How I Met Your Mother, as the cast and crew filmed their November 26 episode with several special guest stars. I also got my very own script (whee!), and director's chair (with the makeup artist's name on it! But still exciting!), from which to watch them tape the elaborate Victoria's Secret fashion show after-party that caps the episode. But let's allow star Neil Patrick Harris (pictured, center), who plays Barney, the show's lovably psychotic lady's man, fill you in on the plot:

"Last season," he explains to EW, "we did a whole long riff on how everyone lost their virginity, and the understanding was that Barney would have lost his in an incredibly awesome way, with four chicks when he was, like, 12 or something. But it turns out it was actually with his mother's 57-year-old, Menthol-smoking friend Rhonda, and he was 23.

"This was granola Barney," he elaborates, "very young and wide-eyed and working in a coffee shop, and he worked with this girl and she dumped him. So his brother helps him get laid by Rhonda. Then it turns out that his brother told her to claim that he rocked her world, which kind of catapulted Barney into becoming the Lothario that he thinks he is. So when he finds out about his brother, it throws everything off-kilter at the most inopportune time-a Victoria's Secret show."

Shameless ratings ploy? Probably, and a blatant network cross-promotion as well (CBS will also air the real upcoming VS runway show Dec. 4), but—surprise!—the girls sail through multiple takes like pros, trying out different line variations and managing to somehow come off both sexy and demure in towering stilettos and tiny wisps of dresses that wouldn't cover a dinner plate, let alone a grown woman. Almost across the board, the girls don't know much about the show. "We travel too much," says Brazilian Alessandra Ambrosio, whipping back her long, chocolatey mane. "It is only programs on airplanes, you know?" And even Klum admits between takes that Dora the Explorer is pretty much the only thing (other than Project Runway, we presume) that gets regular play in her toddler-filled house. Still, they all throw themselves into it. VS Angel and Sports Illustrated swimsuit star Marisa Miller, admits, "It's so cool just to watch and learn how they do it, and to get a chance to go beyond still pictures and actually be speaking lines. I'm going to make my whole family watch this, for sure."

The (mostly) first-time actresses should be proud, says Harris. "I was pleasantly surprised. Some of them had never spoken a scripted line before. I expected they would come in robotic, but they seemed to be enjoying themselves. Heidi was great—boy, she ad-libbed all over the place. She convinces me to go back and confront Rhonda, in order to reclaim my mojo." Indeed, Klum, in a torrent of inscrutable German, makes the onlookers (there is no studio audience on HIMYM) and party extras laugh into their prop cocktails take after take. Barney, of course, having lost all his game, merely manages to make a spectacular fool of himself (boobie jokes galore) in front of the girls, until Heidi takes pity on him and guides him back to safety, a sort of Supermodel Yoda.

Also along for the ride? Buddies Ted (Josh Radnor, pictured, right) and Marshall (Jason Segel)—there mostly to unsuccessfully run interference on Barney's spectacular flame-out with model after model. "It's not the worst job in the world," Segel says with a smile, "Working with these women." Indeed, with the show's female regulars off-set for the day, he snack-cheats on TV wife Lily (Alyson Hannigan), sneaking off with Aussie model Miranda Kerr to craft services to grab some onion dip and delicious little crispy potato chips. "It makes your breath kind of funky," Kerr confides, "but it's so good!" Fortunately (or maybe not so much for the male cast members), there are no kissing scenes in this week's script—and fortunately for me, they leave me some dip. Two thumbs up, CBS catering!

At the end of the day, the models begin to droop (they're basically doing what the other actors have done all day, but in five-inch heels and with constant hair and makeup touch-ups), and the party extras talk quietly amongst themselves. Klum, still flawless in a sparkly metallic sheath, playfully demands that Segel bring her something sweet from the snack bar, now juggling cell phone calls and interviews by various visiting entertainment programs on the show's bar set, while Ambrosio rushes off to catch a 6 p.m. flight, and Harris types intently into his laptop at a desk on the living room set. "I have to say," he grins, "it was incredibly bizarre and sad to have to be that much of a tool in front of the most gorgeous women in the world all day long. But we have a pretty good group here, don't you think?"