Devil's Night

THIS IS ALSO POSTED ON AO3

Y/N started at the BAU almost 2 years ago and her and Emily's bickering started on her first day. The pair constantly throw insults at each other along with glares and eye rolls, the team are used to their petty arguments - it doesn't stop them from solving cases together.
What will happen when the pair have to go on an undercover mission as a couple, will living together change the dynamic of their relationship? Will new feelings be recognised?