It was just to fill a hole; feed a need for them both. A pretend (and secret) engagement to cauterize the loneliness in them both. No feelings involved. 

Yeah, right.

Meanwhile, Spike is intent on tracking down the soldiers that put a chip in his head and enacting some very much needed comeuppance, and as luck would have it he's not alone in that goal.

But she’s in way over her head with only three days to learn the skills she needs to avoid utter catastrophe. With stakes high and resources low, Buffy has no choice but to turn to an unlikely source for help. Can they somehow find a proper rhythm and work in perfect harmony while dancing around the rising tension between them?  
 

Or: Spike teaches Buffy to waltz.

A Holiday miracle, set between “Wrecked” and “Gone”. Dawn invites Spike over for cocoa, sparking something new and different between her sister and Spike.