Ryou Bakura was full of surprises.
Mariku learnt that the first time when he bit down slightly too hard during a heated kissing session on the smaller boys couch. Drawing blood from the boy's pale neck. Instantly scooting away with eyes full of concern and guilt. What he had expected was a cry of pain and a hurt expression that would pierce his heart. What he had not expected was the sultry moan that rose from the slender form under him and the whispered command to "Bite harder."
That was just the start of it.
After a particularly nasty argument, Mariku had grown angry, and for the first time, had hit Ryou. His open palm striking his cheek with a loud slap. The disgust and horror had taken over him instantly, darting forwards to comfort and apologise. He'd expected tears, more shouting, maybe even a slap in return. But the when he saw the look in Ryou's eyes he could only stand there in confusion. Not that he had long to figure out what was going on, Ryou's white fingers knotted themselves painfully in his hair and dragged their lips together, kissing with a never before seen hunger and growling lowly in his throat.
One time Mariku had become jealous that Ryou still spent too much time with Bakura, walking in on the Thief pinning Ryou to the wall and getting the wrong idea. Mariku pulled them into bed with possessiveness flooding through his veins, whispering into Ryou's ear that he was a dirty whore even as they writhed between the sheets. Ryou, suddenly growing more vocal as he reached his climax, far earlier than he usually would before staring at him with unconcealed lust and flipping them over to 'go again.'
He had a habit of suggesting or casually mentioning kinks that Mariku had never even heard of. One week it was handcuffs, the proper kind, steel, with a working key, bought from an online sex shop called 'Bedroom Sins.' The next week he asked him what his opinion was on wax play as he washed up, the plate in Mariku's hand shattering on the tiles. He returned home later with a bag full of vivid red candles and that gleam in his eye that Mariku could never resist.
Of course it wasn't all so extreme, he liked the normal rougher stuff too, though he tended to take it to the next level. Scratches would need to draw blood and remain on his skin for weeks for him to be content. Hair pulling would make Mariku worry about premature balding and think about scalping scenes in gruesome horror films.
Valentines day had brought a new item to their bedroom, as well as a word that made Mariku nervous the moment he heard it.
Hematomania. Apparently it was a fetish for blood, which explained the elaborately jeweled dagger that Ryou's online shopping had produced.
Mariku felt he had to draw the line somewhere.
Even though he'd never tell Ryou, he liked it the best when he could just hold the small boy close, smell his scent and kiss his soft lips gently.
But he was a Yami, a creature formed of anger and hatred, so he had to fake enthusiasm as he hurt the thing most precious to him, no matter how much Ryou liked it.
All he could do was accept his ideas as they came, and treasure the precious times when Ryou just wanted him and his touch.

I feel I should offer some form of explanation for this :P
Basically I had an idea that Ryou could look all innocent and cute but would actually be a freak in the bedroom.
Then I thought it might be cute if Mariku indulged his.. fantasies, but actually just liked regular sex :)
So yeah, various kinks here, pretty much all my own :P

Also, scalping is where the forehead is slit open and then the scalp is ripped off, hair and all.