Gaining

If you ease into eat, like eating until you're full, then just a bit more, it's easy. I, and I feel most gainers here, stuffed ourselves to a bit of pain occasionally instead.

I eat verrryyy slowly. When I started gaining, I would gorge and binge much more frequently—but this often led to indigestion, some nausea, and even vomiting on a few occasions (waste of calories!) So I started “grazing” (with some occasional binges) and have found this tortoise-like approach works well both for maintaining and for a slow gain.
On those rare instances where I do stuff myself to or beyond capacity, I get so turned on that the endorphins seem to cancel out any pain.

Going to sleep over stuffed, sucks sometimes.

My feedee is a masochist, and I am a sadist. So we both like it when he eats to the point of discomfort. I also keep him insanely horny during this time too. It helps that we don't go too far.