The hole realization...

I'm pretty sure his milk hole will need some input.
Hahaha, what?
Otto has three holes. The milk hole, pee hole and poo hole. At this stage, he's, generally, upset because either excessive output has occurred from one of them or the milk hole needs input. The milk hole and pee hole get the most use.
Wow, you've really given this some thought.
Technically, the milk hole doubles as both a milk and cry hole. So you could say he has four holes. That could be confusing though...
You may need more sleep.