Normally I'm very good at forgetting the awful ones. Sometimes the good ones, too... but there you go.
I happen to remember this because it only happened a couple of weeks ago. Strictly speaking, it doesn't qualify as bad sex, but it definitely belongs here.
My BF happened to be visiting, and we're cruising the apps for a little 3-way fun (and just to see what's out there). Suddenly I get this message (on Grindr I think) out of the blue from a guy over 100 miles away who wants me to fuck him that afternoon. Apparently he's driving through my (rather small) town on his way from his city to his final destination about 5 hours drive from there. And took the trouble to do the searches for guys along the way (which is a pretty substantial pain) and pick out the one(s) he likes. I'm flattered.
So I explain my BF is visiting and that we'd be cool with a 3some if he's up for that. Pictures are exchanged. The guy is quite nice-looking - mid-40s is my guess and well worked-out, obviously takes care of himself. My BF is a teddy bear type, furry and round, and I'm a daddy wolf, and both of us are in our 50s, decently preserved for our ages. I mention that my BF would be into 69ing him while I fuck him. He gives me an ETA of 3-4 pm.
Along about 3:30 or 4, he contacts me saying he's been stuck in traffic for half an hour (true, I can see it on Google maps) and will be delayed. I do the math to get a new ETA and get 6pm, so obviously he was running late already. But there really was traffic, and we don't have plans, so fine.
He shows up (right when I expected) and yes, he's hot, but he says it has to be a quickie, which doesn't surprise me nor put me off, I'm fine with that. So we cut to the chase. Everyone into the bedroom and get undressed. He's clearly very into my dick, although when I suck him off a bit, he's not getting all that hard - he's just vocal about how much he likes it and wants it. Fine, I guess he's more of a bottom, but that wasn't mentioned and it's cool.
It doesn't take long before he's bent over the bed anxious for me to fuck him. Well, BF is kind of left out in that position and is clearly interested in sucking the guy, so I flip him over and put his feet over my shoulders. I grab the lube and am just applying it to my dick as my BF goes to suck him, when...
He suddenly bursts out with "I'm sorry, I can't do this," jumps up and slaps his clothes on, and bolts for the door! By the time I can pick up my phone he has already blocked me.
I'm pretty sure he could have figured out that it wasn't going to work before I got to the point of lubing up. Just sayin'.
But whatever. Karma's a bitch, dude. Hope she dishes you out exactly what you deserve.