@Background Pony #E754  
No.
 
A headCANON is a set of ideas that are made about a story by the viewers/fans. These are in no way official or CANON unless confirmed by the original creators of the work in question.
 
This is a headCANNON:  

 
Know the difference; it could just save your life.

@Background Pony #E754  
Set in the future. Rarity is still in the human equivalent of her 20’s in the show.

@ze  
Ain’t that the same thing?

@Background Pony #E754  
How big is the age gap? We know he’s as old as her cutie mark as the Mane 6 got theirs at the same day.  
8 years isn’t that large. If Spike is say 20, then Rarity is still below 30. Plus, he’s a dragon and his development is not like any filly or colt in the show, being raised in Canterlot Castle and all.  
Maybe he will get over it, but not that soon, especially if Rarity returns his affection, like in this artist’s headcanon.

@Background Pony #E754  
You’re thinking of a headCANNON.

@Background Pony #AAFF  
Plus I think by the time he grows up he will get over rarity. Maybe find another dragon and make babies and not abominations.

@Background Pony #E754  
Spike is what, 10, and Rarity is .. probably 20 at most? Somehow I don’t think 28 is a wrinkly old lady. At all.

@lumpfish  
Also a headcanon sounds awesome. how big is the explosion when it fires?

@lumpfish  
Ah so spike is into grannies eh? Kinky spike seeing when spike is old enough rarity would be all wrinkly. Like Granny smith. Ew. Spike could do better with someone his age like another dragon.

@Background Pony #E754  
But, ya know, go somewhere else to bitch about it.

@Background Pony #E754  
But this is in a headcanon future (where Spike has matured) set by the artist. If you don’t like it, that’s perfectly fine.

@SquiggyBomb  
But there’s no serious relationship with them though so this can’t be her daughter. Plus spike is too young to know what sex is.

@Background Pony #E754  
Try telling that to her husband, Spike.

@The Neutrino  
But rarity has no daughter.

@Background Pony #E754  
Her daughter, you insensitive prick.

The fuck is that abomination on the right?