That is... more than a little surprising, honestly. But not unwelcome, if he's honest with himself. He and Bull have a perfectly open, perfectly pleasant physical relationship. But it is different from the one that he has with several others on board.

After all, he'd be lying if he said that the effort to frame that lovely body was just an aesthetic desire. Perhaps for everyone else, the clothing was about them, but when it came to Bull, it was about them. Another way for Clark to wrap his hand around the other man, leave his mark on him, as subtle as it was effective. Most of the barge folk had no desire to be confined to anything, but Bull wanted to be claimed and Clark was always happy to capitulate to such a request, as much for Bull as for his own selfishness.

But to see Bull pick up on the cue... to submit, willingly, without even asking. He couldn't make his touch harsh if he wanted to, he's so very pleased. His hand settles at the back of Bull's neck, sweeping down to run along that firm jaw.

"Before we do anything," Clark says quietly, "I need to know: is this a thank you... or a request?"