Man, the things I'd do to a Patcho that size.
With a gut like that, you know she's gradually stretched out her stomach to the point where a would-be filling dessert becomes a mere snack. You'd need a truly obnoxious amount of food to get her nice and stuffed. I'm talking about full-on entire cake, washed down with a half-dozen milkshakes. Woe is you, right?
That said, your chubby-chasing ass is gonna be the one preparing and hand-feeding all of it to her, bite by bite. See, Patch's steadily growing waistline really keeps her from moving around much. What, with that bulbous mound constantly leaning her forward as it seeps down to her gratuitously bloated thighs. The end result of her limited mobility is a deliciously ironic vicious cycle of idleness.
Oh, you thought Patchouli was already a shut-in no-lifer? She'd be a borderline hikikomori with an extra few dozen (perhaps hundred if you like em *really* big?) pounds added to her belly and already-plump thighs. Yeah, she'd probably be a little reluctant to let you have your "way" with her, but many a night out to dinner together would change her mind in your favor. That, and with Koakuma now handling all of the librarian's duties.
Nonetheless, it'd all be worth it just to see just how much Patch could eat this time before her belly could handle no more, the tightly held together skin bulging outward up into the air as she slumps backward on her chair, legs spread apart to make room. That's entirely your doing. Under normal circumstances, she'd be hard pressed to eat herself into such a state... but a little motivation from a third party never hurt anyone. Right?
In her lethargy, she'd signal you to get closer. Not speaking directly, of course- instead curling her index finger in a "come here" motion. Talking went out the window in favor of warm panting and wheezing about 2 or 3 milkshakes ago. Hardly surprising, given her asthma. I suppose being filled to the brim with your labor-of-love had something to do with that, too. Your eagerly-caressing hand would start drifting down her abdomen, Patchouli's cheeks blushing a flustered pink as you began to grasp a certain "special spot" on her body. Although, I'm unsure if I can go into such detail on a blue board.
I'm sweating just thinking about it.