Looking for a story. Guy fucked at bookstore while he fucks GF

Hey, I hope someone can help. I read a story not too long ago about a guy who goes to a bookstore with his girlfriend. They end up in the back room with the guy that works there.

The main guy ends up fucking his girlfriend with the bookstore employee watching. She puts a but plug in his ass while they are fucking but the plug falls out and then the guy who works there fucks him. But the girlfriend doesn’t know.

Source: reddit.com/r/eroticliterature/comments/l37x35/looking_for_a_story_guy_fucked_at_bookstore_while