Jon Cryer has stories to tell that might sound unbelievable. While his tales of Charlie Sheen’s excesses and bizarre behavior might sound outlandish — yet believable — Jon Cryer has had other experiences that rank right up there.

His new memoir is titled So That Happened, and is full of just those kinds of stories. In one segment, Jon Cryer recalls being on set for a Robert Altman film in which the actors are supposed to be pelted with bird feces.

Things did not go exactly as planned, and Robert Altman was forced to take matters into his own hands to make sure the well-dressed party-goers represented in his film got shit on properly.

What got even weirder was that a bevy of A-list actors repositioned themselves in the scene to make sure they got bird crap on them.

As Jon Cryer observes, after years working with Charlie Sheen, “this wouldn’t even be the weirdest day of my career.”

The director yanks off his headphones and wearily barks, “I’m pretty sure doves don’t s— sideways! Am I right? Anybody?!” …

The scene we are shooting is Randall’s sister Lenore’s wedding. Pretty much the entire cast is in it. So on my first day I get to work with both a director I revere, as well as performers I’ve admired for ages. I’m in the big leagues. I’m getting my chance to find out how the actors who’ve made it ply their trade. To discover exactly how one of the all-time great directors makes his genius manifest. It’s going to be amazing. If only they can figure out how to get this bird-s— thing to work.

The crux of the scene, as Bob imagines it, is that the Schwab family emerges from the chapel, followed by the auspicious release of a flock of doves, signifying to all that our clan is the gauchest of the gauche in terms of egregious displays of suburban American wealth, at which point — big joke! — the doves would poop on us. Take that, richies!

But as I said, this guano business is easier said than done. So after Bob’s minor outburst, he emerges from his trailer, where he’s been watching us on video monitors, with a certain if-you-want-something-done-right-you-have-to-do-it-yourself determination. He confers with his special-effects guy (it’s possible it’s Steve), who runs off and hurriedly gathers a large yellow mixing bowl and several ingredients easily found in a refrigerator or pantry. He throws the assortment into the bowl and mixes fiercely. Meanwhile Bob motions to one of the grips, who grabs a ladder and rushes in. The special-effects guy (thanks, IMDb, definitely Allen) hands Bob the bowl and Bob sighs.

Imagine, if you will, this master American filmmaker — the man behind “The Player,” “Short Cuts,” and “Gosford Park” — climbing a rickety aluminum ladder, perching his shall we say portly frame on the top while a crew member nervously holds the ladder in place, and, as his actors step out from flung-open chapel doors, hurling down on us healthy dollops of very realistic-looking ersatz bird feces (see below for the recipe!) with steady, consistent authority.

As cameras roll, Bob lobs bogus excreta with the artistry of Jackson Pollock. … But I start to notice a curious phenomenon. I haven’t been hit and, for lack of a better description, I’m feeling left out. My gut tells me the audience will really enjoy seeing my character get nailed. So I begin jockeying into position to put myself in the line of poop fire, much the same way an outfielder adjusts to get under a fly ball. I look around and realize that all of the actors I was looking forward to working with, the ones I truly respected, are doing it too! There’s Jane Curtin gliding sideways to snag a faceful of avian dookie, Paul Dooley expertly catching some on the shoulder, and future “Sex and the City” star Cynthia Nixon animatedly yakking with a background performer as she stealthily positions herself to receive an admirably viscous splotch in her hair.

Looking around at this surreal scene, I could not help but marvel at the caliber of performer hoping to get s— on by Bob Altman. I thought, Welcome to showbiz, Jon.

And as it turned out, this wouldn’t even be the weirdest day of my career.

Not even close.

Robert Altman’s Famous Mock Bird S— Recipe

Ingredients:
2 quarts sour cream
1 large mixing bowl
4 Tbsp. ground black pepper
2 oz. black rubber bands

Add sour cream to mixing bowl. Mix in ground black pepper.

Finely mice black rubber bands until pieces are rough 1/8-inch long. Add rubber bands to mix.

Stir vigorously.

Take palette knife, scoop up generous dollops and drizzle eager young actors with Mock Bird S—.