A little toot from your rotund backside gets his attention, and with a sly smile you say "ops, seems like its time for one of your important tasks. Carry me to the bathroom". After some difficulty he gets you on his back for a piggyback ride, the strain from your bodyweight somewhat made up for by the pleasure he secretly enjoys feeling your huge breasts squeezing into his back.
After ten huffy and puffy seconds a loud wet fart bursts wetly into your panties, followed by some low airy puffs, and a heavy "I-need-to-poop-right-now" smell envelops you both as well as the hallway to the bathroom.

"Step on it" you whisper slyly into his ear, "you DONT want this on the floor."

As he now red-faced and huffing brings you into the bathroom, another heavy burst of rectal gas echoes around as he puts you down next to the toilet. "excuse me" you say unable to prevent a few giggles. But now the need is severe, you are glad the relief is imminent.

He makes a move to leave, but you snap "stay!" at him as you swiftly pull down your pants and panties and plant your wide hips firmly on the throne with a sigh. Swinging your hips side to side as you settle down on the throne, you tell him his duties with a smirk on your face, as bassy blasts starts to rattle into the bowl below you when you relax and prepare to unload your ex.