Author's Note: First attempt at writing not only this ship, but from this canon. Well, enjoy!
"You want to know why you and the she-demon never worked?" Spike drawled as he advanced on Xander, backing up the brunet until his back hit a wall. "You were craving something else," he purred as he slid a leg between the human's.
Xander's breathing hitched. "That's just a-" he cut off with a moan as the vampire pressed.
"Physical reaction?" the blonde drawled and his companion nodded mutely. He smirked, as he shifted his leg, rubbing his thigh against the brunet's telling bulge. "Well since you're single, you're free to indulge, aren't you?"
"I can't believe I'm going to say this," he breathed, licking his lips, "but, don't stop."
"Wasn't planning on it," he purred, pressing harder. He came. "Good boy," he praised. Blushing hard, Xander opened his mouth, and Spike covered it gently. "Thought you'd prefer it to 'pet'," he remarked and lifted his hand.
"All right," he sighed.
Spike smirked. "Answer me something. Honestly." He waited until Xander nodded. "She ever make you feel that good?"
He licked his lips. "No, but that might have more to do with the thrill of the forbidden."
"Hmm," he hummed before his lips curled in a tempting smirk. "Come into my parlour, and see how much is thrill of the forbidden, and how much just feels good," he tempted as he gracefully stepped back. He held out a hand to the brunet. With a swallow, Xander took it.