It's not a touch Sirius is expecting even with Kieren's gentle, teasing touches. His muscles tense instinctively at the intrusion and he lets out a rough, surprised sound, hears it echoed by Kieren half a second later.

His wand is too far away, but Sirius had spent years and years perfecting certain wandless spells and he reaches down now as he whispers an incantation to make Kieren's touch suddenly much slicker. "This," he breathes shakily, his hand then wandering to curl around himself where he's already starting to harden once more. "This is different. Fuck."