THIS QUESTION BOTHERS ME TO THIS DAY

SOMEBODY

SOMEBODY TELL ME

The eternal question.

@HorsesandMuchMOAR  
The definitive solution.

The choice to the right.
 

I don’t see why this is up for debate. We’ve exclusively seen the second option done in the show. It makes the most sense. End of story. =P

Because the little ponies are slightly anthropomorphised, the second one makes a lot more sense - the forelegs can act as arms, so should be treated as part of the pony’s “upperbody” and thus don’t need to be covered by trousers.  
Also if a pony wore trousers in the first way, they wouldn’t stay up very easily, they’d keep slipping down around the midsection (and maybe slip off entirely). A compromise could be reached by using the first way, but raising the trouser’s belt-line up to the neck, so that they would be able to stay on properly. But really, that wouldn’t be a pair of trousers any longer, it’d be an overall/coveralls.
 
…yeah, I’m definitely going with the second one, it just makes more sense. If she was wearing a top as well (say, a blouse), that would cover the forelegs and the front part of the torso. It just seems much more logical and straightforward to me.

Second one.

Pony wears no clothes: such a nice and proper pony.
 
Pony wears pants low enough to let her tail out: whore!

Oh look! That stupid meme.  
Now in pony form! ;)

The one on the right makes much more sense in human retrospect. Only covers the forelegs as it should and no more. Because a shirt with the one on the left would not look, nor fit well.

This pic is kind of giving me some sparkage imagining that view of the pants on the left from the back… just imagine!!

the left one looks painted into her body

@Background Pony #BCB8  
I love how rarity seems so well off and her dad has a simple little mustache and straw hat. Prob a nice robe, but i can’t tell

@Alex Vostox  
For a centar, yes.

The answer to this question I guess?
 

The left one seems more logical.Add some pockets and you have a good,practical pair of ponypants

Logically, #1 since all four appendages are legs, but with the butt covered, unless it’s a tramp pony. Essentially a combo of the two.

I implore you to look at Rarity’s mother  

This is actually based on dogs but still, here is the real answer, straight from the President.

@Legioner8  
“No, no Bon Bon. It’s like this.”

@TheOtherPinkiePie  

@TheOtherPinkiePie  
*It

I would work better if she was Lyra.

I like the way on the left.
 
You know, it being more revealing, and not complicating my tail and whatnot.

are you trying to turn this into a meme?