EXCLUSIVE: Nick Offerman and Megan Mullally, the husband-and-wife team who play ex-spouses on NBC’s “Parks and Recreation,” have joined the cast of Lionsgate’s laffer “Gay Dude” along with Gary Cole and Brian Geraghty (“The Hurt Locker”).As Variety first reported, Nicholas Braun and Hunter Cope are set to star as Michael and Matty, two best friends who vow to get each other laid for the first time before their senior prom. Their quest takes an unexpected turn when Matty tells Michael that he’s gay. Offerman will play Braun’s father, who finds him Googling the term “gay,” but couldn’t be more supportive. Cole will play Cope’s conservative father, who likes women to be women and men to be men. Mullally will play Cope’s mother, while Geraghty will play his annoying older brother, who still lives at home. Dakota Johnson (“The Social Network”), Dreama Walker (“The Sitter”) and “Modern Family” thesp Sarah Hyland co-star in the low-budget pic, which Chris Nelson is directing from a Black List script by “Parks and Recreation” scribe Alan Yang. Laurence Mark and David Blackman are producing for Laurence Mark Prods., while Jai Stefan is also producing. Production is currently under way in Vancouver. Offerman, who plays Ron Swanson on “Parks and Recreation,” will soon be seen alongside Will Ferrell in the Spanish-language comedy “Casa de mi padre,” as well as the indie “Somebody Up There Likes Me,” which he also produced. Cole, who recently received rave reviews for his turn in “Superior Donuts” at the Geffen Theater, will soon be seen on TNT’s “Ricochet.” Mullally co-stars in Lionsgate’s motherhood comedy “What to Expect When You’re Expecting” and is repped by Gersh. UTA-repped Geraghty will soon be seen in Jamie Linden’s “Ten Year,” which will debut at the Toronto Film Festival. Cole is repped by ICM and manager Barbara Gale of Envoy Entertainment. Offerman is repped by attorney Jamie Mandelbaum.