Okay, so I'm not sure about the sincerity of Zerrie. I think it's most likely a PR relationship seeing as both One Direction and Little Mix both have the same management company. It's also convenient that Little Mix was a failing act and then "Zerrie" happened and LM becomes big all of a sudden.
But anyway (no one's gonna read this anyway), I happen to quite like Little Mix, so I guess Perrie would be my favourite girlfriend...
(I really need to elaborate. I would have said Larry or Ziam, but I believe that Larry is actually a romance and that Ziam is more than a bromance. Plus, Ziall is cute.)