Season one: Beckett is absolutely appalled by the idea of marrying Castle
Season two: She rolls her eyes, but thinks nothing of it.
Season three: The wheels are turning.
Season four: They go to a wedding on a date together.
Season five: Just when it looks like their relationship is over, she sees the fact that he’d rather uproot his life than let her go after fighting so hard for her.
If she doesn’t say yes I’m gonna be pissed.