What is "blubbing"

Usage examples of "blubbing".

And when I looked at her across the room listening so intently and looking so much her real self, honestly, I found myself blubbing in a most unsuitable way because of course I'm supposed to be the strong one.

Or could it be that he was a psycho, and he would pull your head off with his bare hands, blubbing all the time?

Now you just stop this stupid blubbing and get right back in there and see to him.

He now started blubbing like a baby, sobbing his heart out, and swearing his undying gratitude to Trinket.