Totally am onboard
Nick being at her place at end of
16x02 
and opening up to her about Reeves
Very touchy of Nick in
16x03 even if they are under fire, very protective of her
ETA sensing a lot of off-screen bonding
making their own code,
Goat Yoga
These 2 surely go on "undercover ops" together a lot
ETA 2 its TOTALLY being lead up to these two
even if I didn't already know, the clues are being dropped
ETA 3 
babysitters for Christmas
These two bonding with the baby
These two would make perfect parents
Nick starting to realize he's feeling something for her