Jack wasn't too far away doing roughly the same thing with Gabriel's younger self. As long as Sylar allowed Jack to help him clean up, that was what he'd do. Blood was difficult without a little assistance after all and Jack rubbed soaped up hands across Sylar's as they stood by the sink, water running.

He didn't say anything. There were no questions asked, no apologies demanded.

Jack knew what it was like to have kids and he knew what it was like to house murderers. That didn't mean that any of this was easy for him. Mohinder could heal through physical affection and understanding, but what about Sylar? Jack could attempt to find him another, less homocidal Luke when the lock lifted but he didn't think that would be a good idea.