"I don't think that magic would have any use for something like me?" Keyword being something.

With a final kiss to Viktor's forehead K releases him as requested. Hoping to hide evidence of his brimming tears, he gives his face a hard scrub beneath the running water then shuts off the shower and steps out. He pulls on a bathrobe and offers another to Viktor before bending down to start gathering their dirty clothes from off the floor. 

Might as well try to be useful and wash Viktor's robe for him. By hand, he thinks as he carefully examines the material, just to be safe. He knows it has sentimental value. He doesn't want to risk ruining it.

"I'll wash it for you," he says as though it should have been obvious that he'd never just throw it out. "And before I do, can I get you anything?"

After the wild rollercoaster of a reunion that they've had, with the highs of declarations of love and intimacy followed by the abrupt plummet into the current low K finds himself in, trying to keep his hands and mind occupied with more mundane tasks for a while might help.