@MezzoDragon  
I’ll explain it then:  
First off (to avoid misconceptions) Alicorns being confirmed immortals is just fanfiction.  
All we know is that Celestia and Luna are long-lived enough to be around for a thousand years. Dragons are also known to be long-lived creatures, and as stated by the show their naps alone last 100 years, which implies a ridiculously long lifespan. Most fantasy media often depicts them as either living for many millenia or being downright immortal, so they’re all in the same boat.
 
That means we don’t know whose lifespans are longer between alicorns and dragons. Which means Spike could outlive them as easily as they could outlive them.
 
Also, Anon could’ve also been reffering to Spike’s close friends, and since Twilight having extended lifespan is both unconfirmed and (as of now) contradicted by one of McCarthy’s statements, then yeah, the common assumption would be that Spike will outlive her.

@ZeroSpawn47  
Not really.

@MezzoDragon  
you know what he meant

@Background Pony #1832  
How will he outlive the princesses?

Well, hel’ll outlive everyone eventually so in a way, this is right.

it’s awful to laugh at, but man is that funny

@Background Pony #F212  
A sticker book or something like that.

Just where is this from, anyway?

What about Zecora and Discord?

@Background Pony #E3E7  
Nope,the no pony commercial.

Forever!

Fuuuuuuuuu

@DJDerpy2013  
Gif is broken for me,but i’m sure as hell it’s a gif with Squidward

@DJDerpy2013  
Fuck let me try again.  

Now that’s just cruel.