because, honestly, I thought Queenie looked more like NEWT'S sister than Tina's so... Secret, Married Lesbians of the 1920's.
Maybe the wizarding world isn't quite so open to it as they like to pretend and it could effect Tina's career...
Maybe they have to hide it from Mrs. Esposito because a muggle tenement was all they could afford and they're just so used to hiding it from their neighbors that it never occurs to them to bring it up at work or with friends...
TLDR: they're married, not related, but they tell everyone they're sisters to keep suspicion off of them.
Queenie/Tina, "Hey mister: she's my sister." (Non-Incest AU)
Maybe the wizarding world isn't quite so open to it as they like to pretend and it could effect Tina's career...
Maybe they have to hide it from Mrs. Esposito because a muggle tenement was all they could afford and they're just so used to hiding it from their neighbors that it never occurs to them to bring it up at work or with friends...
TLDR: they're married, not related, but they tell everyone they're sisters to keep suspicion off of them.