Old Man Stifler has a heart attack while in the middle of banging his nurse. He is rushed to the hospital and the doctors are able to revive him, but then another nurse comes to give him a sponge bath and they start bangin', so he has ANOTHER heart attack. Old Man Stifler is 96 years old by the way. So then some of OM Stifler's family shows up at the hospital, including his estranged son, Stephen Smithler. Stephen changed his name because he's a douche. The Stiflers are standing around OM Stifler who's lying in his hospital bed hooked up to a bunch of medical equipment. He whispers, "Steve Junior, come closer..." and Stephen's like "My name's not Steve Junior anymore, I changed it to Stephen!" What a douche that guy is. "Come closer, son... I need to tell you something..." Croaks Old Stifler, clearly on his last breath. So Stephen the Douche leans in douchily, and Stifler whispers something in his ear. We don't hear what he says, but Stephen looks shocked. Then Old Man Stifler dies. But even in death, he still has a boner.
Stephen's wife asks what Stifler said, but Stephen's just like "Who cares, he was a crazy old son of a bitch." But he's obviously crying about it. What a fuckin' douche. Anyway, we see Stifler's Ghost rise from his old body. The ghost isn't old though, it's Classic Stifler, played by Sean William Scott. Because that'd be fucked up if you became a ghost and were still old. Stifler's like "Holy shit, looks like it's time for someone to get 'touched' by an angel" or something. You know how he is. But then he floats up into the sky, and eventually arrives in Heaven. He is personally greeted by Jesus Christ (Eugene Levy) who's like "Welcome to Heaven, Stifler! It's great to finally meet you, you're like my hero" and he hands him a six-pack of beer. "Come on, I want you to meet my son, Jesus Junior." So they go to JC's house, but they enter without knocking and walk in on Jesus Junior fucking a warm apple pie. Also JJ accidentally ejaculates in Stifler's eye, so from now on Stifler wears an eyepatch.
Later, Stifler and JC are chillin' and Stifler's like "I don't get it... Here in Heaven you just have to snap your fingers and pussy literally rains from the sky." Then he snaps his fingers and pussy literally rains from the sky. JC's all "Yeah, I never get tired of that superpower." Stifler continues, "So what kind of a fuckin' loser would you have to be to fuck a pie? No offense, Jesus." JC tells him that's why he's here, he wants Stifler to help his son. "He even wants to change his last name from Christ to Schmyst!" Then Stifler remembers his own son, and how he couldn't stop him from being a douche because he was too busy getting laid. Maybe now is his chance to make amends or some shit. "Sorry, JC, but your son's a douche. I'm gonna go fuck that naked angel over there." Then he flies away, because you can fly in Heaven too. Jesus smiles, "Oh, Steve Stifler... Truly a king among men." Then he gets a call on his iPhone. It's Satan, crank-calling him. But Jesus knows it's Satan, because he's fuckin' Jesus. You can't trick him. So Jesus just hangs up on him, then he's like "Go-go Gadget Copter!" and the top of his head opens up and a propeller comes out. He flies away, leaving a beautiful rainbow trail behind him.
Suddenly, we flash back to Old Man Stifler in his deathbed. It's the same scene as before so I'll just copy-and-paste from the other paragraph. "Come closer, son... I need to tell you something..." Croaks Old Stifler, clearly on his last breath. So Stephen leans in to hear what Stifler has to say. And this time, we hear it too. He whispers, "You're a fucking douche"... Then he dies. Then a few seconds later some doctors come in and zap him with defibrillator pads or whatever the fuck they're called, and Old Man Stifler is alive again. Stephen says "YOU'RE the douche, not me!" And runs out of the room, like a douche. Stifler says "Huh, it was all a dream... Or was it?" Then he snaps his fingers, and through the hospital window we see that pussy is literally raining down from the sky.