In simpleton terms, Jello-O-ous is when you are wicked jealous of someone of something. Basically, Jello-O is so crazy intense that you're jealous of its fresh dancing abilities - the art of wiggle dance - that you describe all of your intense jealousness using that ratio. The ratio being your jealousness of Jello-O to that of your jealousness of some other object - or person.
"Hey John, how are you doing?" - Waldo.
"Oh, hey Waldo." - John.
"Man, that is one wicked argyle sweater. I'm pretty jealous." - Waldo.
"Oh yea. I can totally see it in your eyes." - John.
"Actually, I'm pretty Jello-O-ous of it." - Waldo.
"Yeah, I think most people are. And I know that the ladies dig it." - John.
"Well, see you later John." - Waldo.
"Peace out, Waldo." - John.
"Hey, where's Waldo at?" - Chuck.
"I think he just went that way." - John.