@immblueversion  
Who may or may not be their fifth cousin removed by a fourth cousin, aka, not blood related in any way.

@immblueversion  
Because the show had the nads to give some hints, it’s basically FlutterMac which has been around for ages, and like the day it aired, this came out:
 

 
The comic has nothing to do with this cover.
 
People always wave away the potential incest by citing its distance. Which the show could not give less of a crap about.

Why do some people cling to the idea of Big Mac being in love with someone who may or may not be his cousin?

@Keith Mowz  
If either lyra or bonbon ever fell in love with a stallion, no one would have any right to complain.

@Ihhh  
In the same way Lyrabon was never established in the show. (Just hint-dropped very subtly.)

@chubbyninja89  
Writers are not required to follow your personal interpretation, they only need to follow what’s directly established in the show, and a romance between marble pie and big mac was never established.

I like to think of Marble and Big Mac as friends who get each other more than lovers. I think they found kindred spirits on one another, and friendship, but not love. Marble’s shyness is just the way she is, not some indication that she was shy because she was smitten. Rather, shy because she is just like that, and we know Big Mac is shy, too. Two quiet introverts trying to make friends with each other. That’s all. :)

@621Chopsuey  
But I guess we couldn’t have it because people are too fucking stupid to understand that concept.

@09MurphyM  
Distant enough to not be considered taboo.

Keep in mind that Big Mac and Marble pie are possibly cousins, so that type of relationship probably would have been too weird.

@Background Pony #8BB1  
Well I would somewhat agree with you, but it seemed that they were genuinely kind of at least interested in each other. And both Big Mac and Marble were known to be pretty shy.
 
And I wouldn’t be surprised one bit if the same thing happened to SugarMac. Really think about that.

@chubbyninja89
 
Characters failing to interpret a scene as we see it is not lazy writing. We’ve seen no hints that Mac ever followed up on the Hearth’s Warming visit like he did here. We saw no effort at all on his part to see Marble again, no suggestion that he wanted to see her. There’s nothing lazy about looking at a couple of ponies awkwardly hang around one another for a couple of days and deciding that was as far as it was going to go. That choice was just as valid as any that would lead to courting Pinkie’s twin sister.

There’s a difference alright.
 
It’s called lazy writing. Or rather non-consistency would work better.

Sometimes I wonder if anyone in this fandom really know the difference or just don’t care.

More like they just clicked, they found somepony they can relate to.

@FanOfMostEverything  
Best an explanation as any.

I just figured Apple Bloom missed the signals there. Or the writer forgot about that episode, but I prefer Watsonian explanations.

As a fan of MarbleMac, I find this headcanon acceptable.

who do you think Big Mac will date next year?

more like possible incest