Imma be real with you I have no direct answer for this question. I can't exactly pinpoint why it's so satisfying to have someone slide on down one's throat, knowing well what fate awaits them inside. Perhaps it was the voracious plants in Wind waker and Twilight Princess that got me, or some of the cartoons. Or maybe I just have a morbid fascination with the serpent like creatures capable of swallowing things whole (which is why snakes are pretty fucking cool don't lie) and there are just many other factors to about it. The bonding experience one shares, the sense of dominance over the other or the absolute feeling of empowerment that one can only live out in fantasies. Either way, regardless of how you look at it there's no easy answer.