One might assume, from both of them enjoying visits to clubs like Incarerous, that they were sexually compatable. One might also assume from the fact that they both identified as tops that they were sexually incompatable. The truth was far more complex. Remus had the dominance and submission urges of the wolf, and Severus, while not submissive, had a taste for sensations stronger than the Dark Mark. Both of them had a liking for rope, for resisting, for provocation. They were able to switch.
Remus had resisted anything he thought might hurt Severus until the day he promised to follow Severus' orders. Severus had him strip, masturbate, put on a little show... and then ordered Remus to whip him with a multitailed flogger he sometimes used on Remus. Remus considered safewording, but Severus' moans when he didn't made him glad he'd tried it. Moans of pleasure, not pain, Severus squirming and gasping... and coming, to Remus' surprise.
Remus wouldn't call the sensation of the whip pain, exactly. He wasn't sure what he'd call it. He'd let Severus do it to him if he wanted, because it made Severus hard, because he got off on knowing Severus got off on it, but he didn't enjoy being on the receiving end the way Severus did. And doing it to Severus nagged at him sometimes, he'd have to tell himself, You're still a good person if you like this. But he did like it, because he loved making Severus come harder, gasping and twitching and oh, Severus...
No, his cruelty took a different form, the form of Severus tied to the bed, helpless, aroused. He'd go down on him a bit, then stop. Fuck himself with a dildo for a bit where Severus had to watch. Then stop. Run ice cubes all over Severus' body, not just his cock or nipples, but his toes, his wrists, his armpits, until Severus was struggling and cursing and demanding Remus finish him. But Severus wasn't in charge here. Remus was, and he stopped and jerked himself off to prove it, shocked at himself. He stroked Severus with come-smeared fingers and murmured sympathetic nothings at his struggles. "You could beg, you know," Remus said.
"Fuck you," Severus said.
Oh, Severus. So fierce and brave, magnificently defiant. He loved Severus like this, and suspected Severus loved him seeing him like this.
He didn't want Severus to be defeated. He wanted Severus to surrender up his trust when he surrendered up his body to be tied. Severus didn't want to surrender.
"I think you're quite probably the sexiest thing I've ever seen," Remus said.
Severus groaned, thrusting up, straining against his bonds.
"I'm not going to finish you, you know," Remus said. "I'm just going to keep tormenting you."