You may happen upon some stray bit of marketing for Jeff Baena's latest feature, see some images of nuns in milk-white habits and scan the words "adapted from Giovanni Boccaccio's The Decameron," and think, "Hmm, seems chaste and dry enough for a Sunday afternoon." Not quite. Taking a page from Monty Python and an entire book from Mel Brooks, Baena only utilizes Boccaccio's text and the 13th-century setting that comes along with it as a vehicle for unexpected F-bombs and wink-wink nuns-in-heat action. On paper, that idea would be intolerable, yet Baena wisely enlists some of today's most wild comic talents, including Alison Brie, Fred Armisen and half the cast of the director's previous genre mashup, 2014's Life After Beth (Aubrey Plaza, John C. Reilly, Molly Shannon). No matter how obvious the set-up – what if men and women of the cloth were … rude and sexy??? – the cast gives every scene just enough of a deadpan spin to sell it, at least for the first hour. After the final 30 minutes come and go, including a frantic detour into witchcraft, you may seek out a convent of your own.