he eats it realistically

“Why did Soos eat his hat during those 3 days? He has a infinite pizza!”

Realistically the infinite pizza was probably supposed to be a one time joke the gf crew already forgot or chose to ignore for the sake of the joke.
Buuut, I have a headcanon that Soos gave the pizza slice to someone he met during the 3 days he spent wandering around and helping people.