So, most of the time, I'm the GM, and occasionally, I jones to just play. So some years ago, I was GMing at a game store in Northern California. I was running a Call of Cthulhu campaign where the PC's were inducted into a secret society that was trying to track and understand the Cthulhu Mythos while at the same time keeping the public from learning anything about the Mythos. So as part of their backstory, PC's had had a minor encounter with the Mythos and thus began the game with a point or two in Mythos knowledge and a corresponding point or two decline in Max Sanity. One of my players, we'll call him Boom, (mostly because he was a former chemistry professor who would routinely cobble together explosives to deal with Mythos creatures, once rolling well enough that I gave him five minutes and his phone to convince me it was possible using 1920's tech to craft a nuclear explosive device. He couldn't and so settled for fire bombs...but since the big bad was a fire vampire they were ultimately useless).

Long story short (too late, I know), Boom told me a new GM was running an old school D&D campaign and he was short on players. I leapt at the chance to play, creating a tiefling mage/thief. I chose spells like spider climb and web and created a character that was part of a cult that had served a powerful spider spirit and that had been hunted to virtual extinction in the area he was from. The GM loved the idea and so we settled down to play. We begin in the familiar Plot Contrivance Tavern and I am meeting the other PC's when the halfling bard goes upstairs with a tavern wrench.

Now when I have a PC that decides to have sex, I have it happen 'off camera', but not this GM. No, what happens is this GM begins a roleplay with the PC that would make the pages of Penthouse Forums blush. Half an hour in, Boom gets a text, claims he's been called into work and leaves. (Not true I found out later)

Another half hour of this ridiculous roleplay (interrupted twice by the shop owner who tells the GM to keep his voice down) and I get a call. I step away from the table to take the call. It's my SO who is very excited because she won a five hundred dollar VISA gift card which let us get ahead on a couple of bills and still have enough money left over to go to my favorite restaurant. I told her to come get me and returned to the table where the GM is red-faced and angry, says I have missed my turn to rp, and the party is now on the adventure without me. I say fine, grab my stuff and leave.

As I'm leaving, the shop owner asks me if I will run something next week so he can tell the GM that he can't keep running the campaign in shop.

TL;DR GM and player engages in an hour long sexual rp that costs him half the party and his spot at the Game Store. The next week I run a very fun Paranoia one shot.