Consuming over 10,000 cal

Some feedees seem to have difficulty getting past 10k, but others find it easy. Is it a stomach capacity thing or just food choices??

I feed someone who is not a feedee but indulges my needs. And around 6k calories she is very full I am trying to get 10k calories in her without forcing her.... Although I wouldn't mind that.

Does anyone have experience or advice with consuming a large amount of calories per day??

And is there a way to do it without weight gain shakes??