I don't know if anyone's already recommended this (and I apologise if they have), but I stumbled across it recently and found, despite the complete implausibility, that I really enjoyed it and so I figured I'd share.
The Truth Hurts... In a Good Sort of Way.
Just a heads up though: it is rated X (ie. NC-17) for graphic sexual content, so be warned.
Of course, that's my favourite kind of warning...
Anyway, the gist of it is:
Kagome gets dosed by the dreaded Shinjitsu Flower. (Flower of Truth) Where can she find solace when her inner most thoughts refuse to stay inside her head? With the great Taiyoukai of course. What happens when Rin can't keep her mouth shut? Hilarity ensues.
Happy reading!