If you are not offended by the idea of a black comedy with cancer jokes, raunchy language and sexual situations set in a hospital room with two cancer patients lying silently in their beds, you are in for some very funny moments during this MCC production at the Lucille Lortel Theatre. You may feel guilty for laughing at times, but laugh you will. Good taste is not on the agenda. Karla (Beth Behrs of “2 Broke Girls” in a promising debut), a struggling comedienne with a potty mouth, tries out new comedy bits on her sleeping mother Marcie (the ever-watchable Lisa Emery). Don (a fine Eric Lochtefeld), a rumpled middle-aged guy dealing with a messy divorce and an unruly son, is visiting his mother Geena (Jacqueline Sydney) who lies in bed with a shaved head and has at most a handful of lines. Don and Karla get off on the wrong foot, but gradually share confidences and grow closer. There are several effective set pieces, either comedic or dramatic, with dry stretches in between. Too often getting an easy laugh trumps plausibility. Even a hilarious sex scene milks laughs for too long. The ending is weak. Nevertheless, the dialogue is snappy, the acting is fine and the attempt by playwright Halley Feiffer (I’m Gonna Pray for You So Hard) to try something different is admirable. The hospital room set design by Lauren Helpern looks extremely authentic and the costumes by Kaye Voyce help define the characters. Trip Cullman’s direction is assured. Those not turned off by the play’s premise are likely to enjoy themselves for most of the time. Running time: 90 minutes.