Title: (C83) [Yuushiki (Usa)] Houseki Hime wa Mou Nakanai (Fate)
JPN Title: (C83) [憂式 (ウサ)] 宝石姫はもう泣かない (フェイト)
Been meaning to post this one for a while.
I suppose the story in it is a bit tragic one if you take the relationship into consideration, but then again Kotomine is a cold bastard.
You can view it here