Dailies | Jason Segel Trains Leslie Mann in ‘This Is 40' Featurette (Video)

Behind-the-scenes look at "This Is 40" features his character hitting on hers while serving as her personal trainer

Jason Segel reprises his role as a struggling physical trainer in Judd Apatow's sort-of-sequel to "Knocked Up" — and his character, Jason, has no problem training Leslie Mann's Debbie for free.

Also read: 'This is 40' Trailer: Paul Rudd and Leslie Mann Laugh in the Face of Domesticity (Video)

"If you were my girlfriend, I would need an anti-Viagra pill to try not to get a boner," Jason tells Debbie in a behind-the-scenes featurette.

The film is directed by Mann's husband, Judd Apatow, who has no problem with Segel, one of his favorite actors, hitting on his wife. In character, of course.

When he's not hitting on Debbie, he's busy berating her friend Barb — played by "Bridesmaids" co-writer Annie Mumolo — for not being as physically fit.

"This is why you're the before picture and she's the after picture," Segel scolds.

Just one of the many jerky zingers we have to look forward to when the comedy hits theaters on Dec. 21, 2012.

Watch the video: