Any grumbling that occurred now he would say was all Sherrinford's blame for getting emotional. It was why Jim looked like he'd gotten in trouble, not looking at the other even when he kissed him and making a small 'hmph' at the nuzzling.
He waits until Sherr seems comfortable and says, "You've ruined the mood." And Jim was simply adverse to romantic inclinations because he often pretended with them. He didn't want to have to try and figure out real versus fake with Sherrinford. In the very least, he spread his arms apart even with his wrists bound to loop over Sherrinford's head and rest on his shoulders. "