"Is this one the story I read on Literotica a long time ago? "
Yes, that is correct and thanks for being a fan. In regards to authorship, also yes, but it's not a simple yes. Not that anyone is asking or really needs to know the details, but years ago, way way back in high school, two friends and I started writing exceptionally raunchy comedy. It became a contest to see who could sort of "out-sick" the others. There's loads of stuff I would be horribly embarrassed to ever publish now, but we had a blast being total asshats back then. We kept in touch long after school, continuing this ridiculous hobby every now and then, sharing stories and quips, et al. We never take this shit too seriously, and certainly don't put as much scrutiny or care in the exercises as our "real" work, but it's often been good for a laugh. This story actually started in its infancy about an aphrodisiac being released at a football stadium.
Both of my friends became professional writers.. one in particular has written quite a few scripts for television and probably many of you have seen some of her work. She makes a much better living writing technical documents now, but that's life, eh? Anyway, a decade or so ago, I offered to publish some of our stuff on lit under one name, and that's how some of these stories ended there. Sadly, the other friend (the one who wrote the original aphrodisiac story) passed away, and though Irresistible Johnson isn't his original tale, he'd get a kick out of the concept of this game.