FWB said he was single. Turns out he's NOT single. Has partner. Is cheating. What do 💀
Why not do what I do? Just unleash some good old-fashioned Stalinist Peoples' Wrath on your FWB's SO.
Works every time. Stalin, for all his other faults, for why yes good gracious he possessed many, remained consistently amazing at orchestrating and unleashing, and I quote, The Peoples' Wrath (seriously, that was the official Soviet phrasing) upon those he deemed Inconvenient.
Here's how. For convenience I'll assume all three of you are male and/or penis-havers.
First, simply hide inside your FWB's seminal vesicle. That's the little fella within a dude's pelvis that stockpiles his spunk, primed and ready for future ejaculations. They're more capacious than you'd think! And more accessible! Just go full-on sycophant for a few hours. Literally kiss his ass. Tell him he's been a Good Boy, even more than usual, and it's time for a Good Boy Reward. Should you play your cards right, then with luck, that wording will induce within him a sneer of such volcanic disgust that he won't even notice you disappearing up his bum and snuggling all cozy-like in his seminal vesicle.
Awesome, Step One complete. Now wait. If your FWB is of such supreme oafishness that he'd cheat on you, sugah, then he's surely oafish enough that your disappearance will remain unnoticed. So twiddle your thumbs for a while inside his spunk-sac, until he realises you're absent, and that the coast is now clear for a bit of cheeky SO-humping.
Rad. Step Two awaits. Mr. FWB will make his way SO-ward; commence snogging; commence humping; and the interior walls of your fleshy condo will commence tingling as imminent orgasm threatens. Ride that white tiger like Falcor in a porno-parody Neverending Story. Surf your sloshy way up FWB's cock and into his SO's rectum.
Now you're inside SO too! Result! Shove your full-sized limbs into his. Pilot his body around from within like he's a glorious fleshy tuxedo. Your FWB will think you're him. Mission accomplished. And now the psyche-destroying mind games can begin!
Now posing as Mr. SO, immediately insist on some fantastic oral from Mr. FWB. If you can concentrically thread your own cock within Mr. SO's, then with any luck your FWB will obliviously suck off both of you simultaneously.
Synchronise your ejaculation with that of your Mr. SO host. Both your spunk-stream and his will thus emerge twirled and intertwined, like extra-snazzy Colgate Sparkle toothpaste (which, by the way, 6yo-me deemed the raddest and most glorious toothpaste in the goddamn universe.) Or Ghostbuster weaponry! Don't cross the streams! This was one of Stalin's favourite Gulag torture techniques, I hear.
Mr. FWB, no doubt a seasoned professional at sucking off both of you, will immediately detect your spunk twizzled with Mr. SO's. He will throb with hot suspicion at, apparently, the two of you bumping uglies behind his back.
The stage is now set for a glorious blazing row. Based on your post history, Tristen, I'm sure I won't need to instruct you on how to inflame and explode this, as it would appear you're a natural.
Godspeed, young sir! Make Stalin proud.