Sizhui intentionally wanted to distract himself. Channeling his thoughts through music helps him focus. When he feels the warmth of the other's energy, he halted his playing in order to receive the energy to heal properly. It's warm.

"No, not hurt. Just worried."

After a few moments, a pause, a slow beat. His fingers pulling on the strings to make a harmonious note. "You can lean on me if you want. I would like that."