From "Reaper's Gale" by Steven Erikson, a fantasy novel featuring a character wearing a magical disguise that makes her appear very fat.
“The woman – sudden centre of attention with most conversations falling away – seemed for all her impressive girth to glide as she moved between the blessedly widely spaced tables, and in her dark violet eyes there gleamed a sultry confidence so at odds with her ungainly proportions that Tehol felt an alarming stir in his groin and sweat prickled in enough manly places to make him shift uneasily in his chair, all thoughts of the meal on the plate before him torn away like so many clothes.”
“He did not believe it possible that flesh could move in as many directions all at once, every swell beneath the silk seemingly possessed of corporeal independence, yet advancing in a singular chorus of overt sexuality. Her shadow engulfing him, Tehol loosed a small whimper, struggling to drag his eyes up, past the stacked folds of her belly, past the impossibly high, bulging, grainsack-sized breasts – lost for a moment in that depthless cleavage – then, with heroic will, yet higher to the smooth udder beneath her chin; higher still, neck straining, to that so round face with its broad, painted, purple lips – higher – Errant help me – to those delicious, knowing eyes.”
It's so vividly written it almost seems like the author could have this fetish. Later in the book the character talks about how much she enjoys wearing the fat lady disguise and how she might just gain the weight for real.
" In a secret chamber – what had once been a tomb of some kind – Ormly, the Champion Rat Catcher, sat down opposite an enormously fat woman. He scowled. ‘You don’t need that down here, Rucket.’
‘True,’ she replied, ‘but I’ve grown used to it. You would not believe the power being huge engenders. The intimidation. You know, when things finally get better and there’s plenty of food to be had again, I’m thinking of doing this for real.” "