Q:

"As big as you please"

What is the meaning of this expression in the following contexts?
1.    “I think we have too many clothes on Sammy.”  Sam nodded and pushed Dean off of him, shucking his pants as quickly as he could, Dean getting undressed hurriedly right in front of him.  Sam watched him hungrily as Dean's body was revealed to him, and Sam reached out and pulled Dean to him, their naked bodies finally pressing against each other, all hot skin and needy hands. 
Dean grinned as big as you please as he touched his forehead to Sam's.  “Whatcha gonna do with that mouth of yours Sammy?”
2. I'll never forget how Petey looked, setting up there on that stool as big as you please. She was flirtin' with that guy for all she was worth. She pulled out that ...
3. “Men,” it said in bold letters as big as you please. Damn. She had walked straight into the men's room. How utterly embarrassing. She turned and fled into the ...
4. From rowdy Creole and Cajun feasts to romantic dinners with sparkling wines, you can go as big as you please (but we hope you have your dinner ressies for ...
From what I can understand, this makes no sense, at least to me, with a literal meaning. So this might be an idiom. In the forth context it seems that it means "as you please". Although they all seem to have different meanings.

A:

A pretty dated idiom which means to the greatest extent possible. I think it's an appropriate phrase for each of the examples you provided. 

This is the type of context in which I typically see this phrase. To "smile as big as you please" is to put on the biggest smile imaginable. 
Without context, I don't know why Petey would be sitting up "as big as you please", but I would guess he's not at all inconspicuous in this potential courtship with the flirtatious hottie. 
The word "Men" was printed in such a (or the most) noticeable manner that it's a mystery that she missed it. 
"you can go as big as you please" attempts to sell the idea that you can have the fanciest dinner imaginable. 

In all of the sentences, the message is that the subject is grand, large, noticeable, obvious, enormous. Or more generally, "to the greatest extent."

