S4: Spike tries to get chip out, Riley/Buffy burst in, Spuffy tussle & realize they like being close

Spike and Harmony have kidnapped an Initiative Dr(?) so he could remove the chip. Buffy and Riley show up and the fight begins. Spike jumps up on the operating table, does the usual threatening speech thing at Buffy, then jumps off and lands on her. They all of a sudden realize they like being that close.

is this the one where he bites her, while he's on top of her and claims her without her realizing?

Is it Pain or Pleasure by Behind Blue Eyes?

An alternative spin on how Out of My Mind would go if Spike's chip didn't go off when trying to bite Buffy. Remember: no pain, no foul!!

Out of My Head by AJ Hofacre?

When you're evil, you're evil, right? Not necessarily. Not in William The Bloody's case, anyway. He's still as big of a Big Bad as they come -- but keep in mind that it's always been his passion that has gotten him as far as he is now. And maybe, just maybe, if that passion were tweaked a little bit... directed toward a certain person... We could see what Spike was really capable of.