Jim, surprisingly, likes being tied up.
Only when Seb does it though, because Seb knows his boundaries (although those are few), and he knows what he likes. That's why Seb starts to draw the knife up the inside of Jim's leg, danger close to drawing blood. Jim always looks so pretty tied up, especially when he's begging. And tonight, he wanted to make Jim beg. Make him writhe. Carve Jim's heart out of his chest and swallow it whole, and make him drown in satisfaction.
That must be why he draws the knife over Jim's sac, not being too light, making it known.
He draws the tip of the knife around the soft skin, and then drags it up the backside of that hardening cock up to the tip, and around the top of it. Here, at Jim's stomach, he presses harder, drawing a faint line of blood, and leans in close, sniffing gently at it, sliding his tongue against the tangy metallic taste, slides his way up Jim's chest to kiss him, letting him tongue the taste from him, letting the knife slide back down, scoring lines against his stomach, drawing blood at odd places, then pulling away from them with a quick turn of it.
Seb pulls back from that lovely mouth, god that mouth he wants to fuck so badly, and instead, returns his mouth to Jim's chest, licking at the blood lines, nipples, navel, down his sides
The knife he's using has a particularly large grip on it. Probably 4 inches long, and two three inches around, curved for a finger grip. He's doing Jim a kindness, tying him down, keeping him blindfolded and guessing. Sometimes he just needs to let go, and so, he pushed that first round knot of the knife's handle in, and lets Jim adjust.
Jim is moaning already, and he's barely even started. God, he just looks so fuckable in this position.
He pushes the handle in further another inch.
Then another, and once more, until it's finally seated all the way to the beginning of the blade
The curved handle is facing forward, and every time Jim slips his hips higher and pushes them back down, he can feel the variance on the grip, and that grip is gripping his ass so tightly.
Seb doesn't ask, doesn't wait for anything, just starts roughly fucking him with the knife handle, until Jim's moans reach a higher octave. He's purposefully ignoring the cock wagging in his face, trying to catch his attention. He almost swats at it, and decides not to. Instead he yanks the handle out, shoves Jim over on the bed, and deftly undoes his trousers. A spit slicked hand gives his cock a once over before he leans over him, and begins the slide into Jim's body. Jim backs up onto his knees, turns his head to the side, hands tied behind his back, ass presented just so, so that Seb can enjoy the glorious sight of his cock sinking into Jim's body faster and faster, using him like he likes to be used.
He grabs a hip with one hand, the knife with the other, and scores a line from Jim's neck to his tailbone, down to where his cock is currently plunging into Jim's body. He draws a line back up, and runs the flat of the blade against the side of Jim's face. Jim turns slightly, so he can run his tongue along the blade, tasting the metal, his skin, and the blood, glorious blood.
Oh god, the sight of Jim licking his knife clean is enough encouragement for Seb to pump faster into Jim's body, the hand gripping his hip, reaching around to undo the tie around Jim's cock and sac, allowing him to finally come.
And he does, less than five pumps later, body clenching and spasming, tightening down on Seb's dick, not letting him go until he's come and spent inside him.
"Say it," Seb growls.
All he gets in return is a groan. He brings one hand down hard on Jim's ass
"Say it," he growls harder.
"Seb," Jim starts, "please."
Oh god, it's enough. It's enough for him to break his rhythm and pump erratically into that waiting body - pumps so hard, and goes still against him, fully sheathed inside him, head thrown back into a wordless cry - a taut arc from where their bodies are joined up to Seb's chin.
And then he recovers, slipping slowly out of Jim's body, doing up his trousers again. He swiftly unties Jim, hands first, then blindfold, allowing him to work out the kinks in his wrists. Jim gets up off the bed, and saunters over to the mirror, appreciating all of Seb's hard work. He goes back, and drapes himself over Seb's body, and kisses him on the mouth, the taste of blood still lingering.
"I liked that," Jim says.
"I know," Seb replies, already cleaning off his knife.