Altruism is in the Eye of the Beholder

"Son, it's a condition not some kinda magical spell! But if it did accelerate or do somethin' else I guess I'd probably embrace it. I just wanna GROW, son." You think again and start to fumble to get up to get the powder. You should make a wish... but what?

Your dad is fine with growing even more and seems open to whatever comes with it. Though your brother is being grumpy about it and you could maybe adjust that attitude. Then again, you feel great in this huge body of yours and you wouldn't mind it getting bigger and to outgrow dad.

"I'll be right back, dad," you say as you grunt and get yourself up, your gut slamming into the floor as you do and your huge ass wobbles in the air with you bent forward.

You feel your dad give one of your huge ass cheeks a pat and smile before you stomp your way down the hall to go to your room again. Once you're squeezed inside you lift a fat hand to wipe sweat off your brow and then grab your wishing powder. In this new reality you have a soda next to your bed instead of a glass of water and you use that to create a new batch of wishing drink. The brown cola flashes and turns into a glittering blue instead and you smile as you take a swig.

You crudely belch and stand there holding the glowing soda as you think about your wish for a moment. "I wish... that the condition dad has mutates and begins to be influenced by his desires. And that it happens to bro and me over time, too."

Your body wobbles a bit as a shockwave runs through the house while your wish takes effect. You set your soda down and stomp your way back to the living room where you see your dad gobbling down more food and seems to be the same. You take your seat next to him again and start to eat while you wait for the wish to do something.