I just find pet names really cute? Especially in the 1920's? Like Percival calling Newt Sweetheart, or Newt calling Percival Darling.? It's just so cute?

Maybe they try to hide from the rest of MACUSA that they're dating and then one of them slips on a pet name. Or maybe they're not even dating yet and one of them just gets hurt and the other is all "oh, darling, let me help you".

I don't even you know guys, pet names are just super cute.