Back on my naughty bullshit, but imagine if you will:
Simon is terrified of having sex because he's worried that he'll hurt Grace. He didn't come out of that blood ocean unaltered; ignoring the whole cosmetic changes, he's now inhumanly strong. If he lost control, even for a second, he could seriously do some damage. But he and Grace are close enough now that he really does want to try it. He can't stop thinking about what it would be like.
And Grace, seeing a problem that needs a solution, goes and finds one. His solution?
Restraints.
(saucy stuff continues under the read more 😏)
Simon can't hurt him if he's tied to the bed, right? And hey, added bonus, now Grace can take his time exploring Simon's body at his leisure, slowly driving Simon mad as he catalogues each and every inch of Simon's skin. Grace has been looking for a chance to observe Simon's physical changes, and now he can take as long as he likes to study them since Simon can't move away. Simon is writhing and panting beneath him as Grace just slowly and meticulously takes him apart without even realizing what he's doing to Simon, lost in his curiosity.
Eventually Simon starts begging, and Grace realized that, oh, yes, they were doing something, weren't they? And then suddenly he's going over the same places he was just touching with his hands, only this time he's using his tongue. Simon starts begging harder.
Finally. Finally Grace climbs on top of him and gives Simon what he's been asking for. Simon can only yank uselessly on the restraints — the xenonite doesn't bend or break, even under his enhanced strength — as Grace rides him, head thrown back, mouth hanging open and eyes fluttering shut with each downstroke. Simon can't hurt him, but god, he can't touch him either, and it's the sweetest torture he's ever experienced. He can only lie there, helpless, as Grace uses his body however he likes.
It's the hottest thing he's ever seen, and when he comes, he comes so hard his back arches off the bed.
After they both come down from the high, Grace admits that he had a lot of fun, and that he's pleased to see how well the restraints held up. Simon absently agrees, still struggling to catch his breath and calm his racing heart.
Then Grace drops the bomb that gets his heart rate right back up again; maybe in the future, once Simon is more familiar with his own strength and is more confident with his control, Grace can be the one wearing the restraints. Would Simon like that?
Simon finds that, yes, he likes that idea. He likes that idea a lot.