'This Is Us' creator jokes viewers will see more of Milo Ventimiglia's butt

BEVERLY HILLS, California -- This Is Us creator Dan Fogelman doesn't know exactly why the NBC show has garnered so much buzz so far ahead of the September debut.

But he's guessing it has something to do with Milo Ventimiglia's butt.

"We’re showing his ass in every episode," Fogelman, who also penned and produced Crazy, Stupid, Love, joked at the Television Critics Association presentation Tuesday. "He doesn’t even have lines in the second one."

The series, which airs Sept. 20 on NBC, weaves together the ensemble cast's intersecting plot lines. Ventimiglia stars as Jack, husband to Mandy Moore's character Rebecca. The series co-stars Chrissy Metz, Justin Hartley, Chris Sullivan, Sterling K. Brown, Ron Cephas Jones and Susan Kelechi Watson.

Without giving too much away -- there's a key surprise moment at the end of the pilot -- Fogelman said the best way to describe the series is like "a dramedy version of Lost."

"Milo and Mandy's storylines jump around in time," he told reporters. "There are four interconnected storylines, with equal time, and one story informs the others. We'll see growth of people as we jump around in time. It's ambitious and I think, for network TV, groundbreaking.”

Ventimiglia, who was rocking a 'stache for the role, told reporters he enjoyed tackling the emotional highs and lows of the storyline.

Their off-screen dynamic helped.

"Mandy and I have had a lot of conversations about Rebecca and Jack as a couple," Ventimiglia said. "I’ve said to her, 'from action and cut you’re my wife.' [Hopefully we'll] make something beautiful and entertaining, something that people can connect to."