So this guy, Rob, has always been a bit... weird. He lives way out in the sticks, has a huge wooded lot, a bit suspicious if he didn't also have a pretty high-powered job at a bank. Odd habits, strange tics, and for some reason he keeps a brick in a fishbowl on his mantle. It's a strange decoration, but he's always told his friends, "Guys, don't ask about the brick in the fishbowl. Just... don't." And they never have, even his best friend, Karl, a psychiatrist.
After a couple years of dating a girl named Julia, she and Rob get married. Karl is the best man. He carries her over the threshold of the house, all the standard stuff. A couple weeks later, figuring that, hey, it's her house too now, she has to know. When he walks into the room next, she asks, "Rob... why do you keep a brick in that fishbowl?"
And Rob snaps. Like, 'Hulk smash!' type snaps. He grabs a poker from the fireplace, catches her right in the neck with it, snaps her neck... she's dead. No blood or anything. That night, he drags her out into the woods, dismembers her, digs a ton of holes and scatters the pieces all about the woods.
The next day, he calls the cops. Julia's missing, obviously. No sign of a struggle, just disappeared. Of course the cops search the woods, but Rob's been pretty meticulous; they find nothing. The case goes cold. Rob mourns with his friends, helps in searches for a year or so, then starts to move on with his life. He falls in love again--another Julia, oddly. A few years later, he marries this Julia.
After a couple of months in his house, she's cleaning up, and takes the brick out of the fishbowl to clean it. It's really dusty; as far as she can tell it's never been disturbed. Rob walks into the room. "You need to put that back in the fishbowl."
Julia turns to him and asks, "Why do you keep this brick in the fishbowl anyway?"
Rob snaps again. This Julia ends up in small pieces scattered out in the woods. But the cops, and even Rob's friends, are rightly suspicious. Two missing wives? The police take him in for questioning. During the interrogation, one of the detectives asks the obvious question, and Rob snaps again. Thankfully for the cops, they're cops, and with no weapons in sight, they're able to tackle Rob and cuff him. And Rob has a heart attack from the physical strain of straining against the cuffs. He collapses; they rush him to the hospital.
Meanwhile, the cops take a much better look at the woods than they did before. They find pieces of the second Julia, and a few bones of the first. Assaulting an officer, two possible murders; things don't look so great for Rob. Of course, things don't look so great for him health-wise either.
The next day, Karl, after clearance by the police, goes to talk to Rob, who is handcuffed to the hospital bed, despite being in ICU. And Rob confesses--to everything, both murders, tells all the details. Except, of course, the obvious one.
Karl says, "Listen, Rob. This fishbowl thing. I mean, I understand now why you didn't want us asking. I guess maybe it was better that way? But man, we need to get you some help, even if that help only ends up reaching you in prison. I'm your best friend, man, I've known you since you were eighteen. Why, Rob? Why do you keep that brick in the fishbowl?"
Rob starts to snap, but he's completely restrained, and his body isn't ready for that sort of strain again. He calms down a bit, then gives Karl a sad look. "All right. I suppose... I suppose it can't hurt to tell now." He sighs, then says nothing; his heart gives out, he codes; the doctors are unable to resuscitate him. And that's the end of the story.
I learned this one at Scout camp a long time ago. The person telling it has apparently entered it in a "worst joke" competition, and strung the audience along for twenty minutes. He won, unsurprisingly.
I considered posting this in the anti-joke thread, but I thought that would kind give it away.
