That i need to find a story i read a long time ago

Years ago I read an excerpt in a magazine that was so hot I used it to masturbate to for years. I really want to find it again. I thought it was from a book called behind the red door, but I'm not sure. Maybe the green door. A woman on a train was having her tits sucked so much she produced milk. They went on to a resort and everyone sucked her tits that weekend. Anyone know the story and how I can find it again?