Twelve Days and Twelve Nights

Ness Montgomery and Alex McIntyre have had this agreement for two years. The twelve days between the town tree-lighting and Christmas Eve are a no holds barred, tell me what you need arrangement.
This year, Alex has decided he wants more from Ness than twelve days a year, and he's going to do everything he can to prove to her he's worth the risk. His ploys involve awkward poems, home-cooked meals, and letting her take control however she wants.
Tropes: Older characters (she's 39 and he's 42), mutual pining, forced proximity and lots of groveling.