Retta, Laura Harring, and Kevin Hernandez also added to cast
The pic also stars Glen Powell and Chris Williams, with Isaac Feder directing.
Story revolves around Osment’s character, who teaches middle schoolers sexual education despite his own lack of expertise in the field.
Monika Casey, Elayne Schneiderman and Dori Sperko are producing.
Morris is best known for his role as Winston on “New Girl” and Retta appears on “Parks and Recreation.” Hernandez was most recently seen in Mel Gibson’s “Get Me to the Gringo.” Walsh can still be seen on HBO’s “Veep.”