I go for adopted path

@Prometheushunter2  
*hiss* Stop ruining it!

NON-blood related

@AstralFrankie
 
that’s only because they’re not actually blood related. if he were, yes it is bad.

but you two aren’t blood related… you hatched him from an egg.

Relevant for both moms and sisters: Remember one key thing above all else…

@Dust Rock  
For the greatest justice.

@Officer Hotpants  
For justice!

… meh. Go for it.

I now ship these two and I also think twilight can fall inlove with spike because 1.) they are not related 2.) Twilight only hatched him with magic

If he’s your son, then – yes. Yes it is.

@SecretTitan  

 
That’s called a Jocasta complex, named after Oedipus’ mother/wife.

@DaringDo42  
Fucking brilliant

Oedipus, put your mother down, you’ll poke your eyes out.

Uh Twi no,that’s (practically) your adopted child

It depends really, in most cases it’s considered taboo, but if both parties agree that this is a natural feeling (also that both never referred to each other as parent/child nor were blood related) then perhaps it’s not as wrong as it may seem.
 
Blood related relationships are risky due to biological birth defects.
 
Non-first named bases can be awkward especially if during a relationship one of the parties slips up and refers to the other as their parent/child instead of first name bases.
 
Despite being rare as long as you follow the rules then it shouldn’t be an issue.
 
Oh it also helps if the relationship throughout life was more friendly than family related.
 

It just makes it kinkier.

@thps48  
Hmmm, she was in the play, but same age? I admit I was wrong that she was the teacher then, but Cheerlee was rocking this:
 

 
When Applejack looked like this:
 

 
Considering that Ponyville has no high school, I’m guessing there is around a 4-6 year age gap between Rarity and Cheerilee at least.

whoo doggy

“Since we’re not related it’ll be okay!”

vavacung is making me like this ship

@Background Pony #D934  
Cheerilee was Rarity’s age in Chronicles.

@vavacung  
Well, if anything, the ponies in the show age slower than humans. Granny Smith is clearly older than dirt, yet she’s still kicking. Cheerilee taught Rarity, and she still looks like she’s in her early 30s. And here’s the big kicker: Our ponies are all adults. In EQG, they are meant to be around 17-18.
 
Basically, time in MLP is weird.

@Background Pony #D934
 
It’s example! I didn’t say we going to compare pony years with dog years. Just showing that human mature faster than human.
 
I said people keep compare pony year with human year. Saying they enter the school at 8 and become legal age at 18 like human. But that is human law and human biology. Who know pony might enter school around 5 years and being legal at 14?
 
I can still see people used warning : All Characters are aged up to 18+
 
But do pony age at the same rate at human? That is my question…

No. Not at all, Twilight. Not at all.