I've spooned with a 550+ lb ssbbw webmodel at a bash, but for circumstances out of both of our control on that night, it didn't go beyond that... Even though we both very much wanted it to.
Figured that was a fun night worth remembering. I can still remember how in awe I was at how massive her belly was when I rubbed it and tried to get my arms fully around it from the back... and remember just how densely PACKED with fat her body felt. I think because she gained so much so quickly, and never lost weight, she was just SOLID. I had never felt a fat woman like that before or since. Truly an absolute unit.
Since no hanky panky was had on that night, the buck for actual sex goes to my wife.
She started our relationship at around 260lbs, and was an extremely exaggerated hourglass figure when I met her about ten years ago. At that time, she was technically the heaviest woman I had been with, but she was so in-shape, I would have still said a few previous partners were "fatter".
But, I certainly can't say that anymore. She is now 410+ lbs and growing, and I'd say her physique is currently most similar to Roxxie at this point. She slowly trended upward over time, and has completely blobbed the fuck out recently.
She looks absolutely incredible, and she's showing no signs of slowing down... She's been getting deep into enjoying nearly constant, full-on gluttonous hedonism for the last few months in particular... to the point that she been looking noticably fatter each week that passes. Good times.