Searching for Spock/McCoy fic

[lilmissspider.livejournal.com]

I wish I could remember where I'd seen this fic, but the idea essentially boiled down to: Spock is astonished by McCoy's stamina in bed.  Of course, that has more to do with the fact that the good doctor can't tell when Spock has an orgasm, and is keeping it up in an attempt to please his new lover.  Ring any bells?