While I do find this funny, let's not forget that there is the chance that Big Mac and Marble Pie could be cousins. Or did we forget the whole episode of Pinkie and Applejack traveling with Big Mac, Applebloom, and Granny Smith to confirm this. And although it was left as a "could be, but we don't know" open ended question, it makes more sense to be with Sugar Bell, Yes I found this extremely funny, but I'm explaining why MacBell happened.