With his new play now in previews at the Atlantic Theater Company, Stephen Adly Guirgis proves once again that he is one of our most entertaining playwrights. Walter “Pops” Washington (the superb Stephen McKinley Henderson) is a black former cop whose career was ended by a hail of bullets in a dicey bar 8 years before the play opens. He has been recently widowed, his son Junior (Ray Anthony Thomas) has been in and out of jail and consorts with criminals such as Oswaldo (Victor Almanzar) who has moved in with them. Their household is completed by Lulu (Rosal Colon), Junior’s girlfriend, who has more curves than brains. We also meet Walter’s former partner Detective O’Connor (Elizabeth Canavan) and her fiance Lieutenant Caro (Michael Rispoli), an ambitious, politically well-connected cop. Last but not least is the Church Lady (Liza Colon-Zayas), a visitor who is not what she seems. Walter’s landlord is out to evict him from his rent-controlled apartment on Riverside Drive. Lt. Caro is determined to do whatever it takes to get Walter to sign a settlement with the city that he has been fighting for 8 years to remove loose ends in an election year and enhance his career. What makes the play so exciting is Guirgis’s dialogue. The language is rough, but the humor is wonderful. The play opens with a discussion of nutrition unlike any you are likely to hear again. Guirgis skillfully softens up the audience with humor so that when he turns serious, the impact is twice as strong. The first scene of the second act features the most bizarre sex scene I have seen on a stage — and there’s no nudity involved. The remainder of the second act was less successful and I found the ending weak. Nevertheless, everything else was so enjoyable that these defects barely diminished my pleasure. Walt Spangler’s revolving set captures the look of a grand apartment that had seen better days. Alexis Forte’s costumes suit their characters well. Austin Pendelton’s direction is assured. If you enjoyed “The Motherf**ker with The Hat,” you will love this one; if you didn’t, you probably won’t. Running time: 2 hours, 5 minutes including intermission.