He could stay but if the carnival loses then he'd go right back to the Prince. He could leave and return but if the carnival wins he'd be right back at the carnival again. There just wasn't any choice anymore.

Tyki's hand doesn't lower in case the skeleton changes his mind and when he finally attempts a piece of apple he'll watch that body language. Ah right, he's hurt just as much as he's weak. If the skeleton tries again he'll assist him by pushing it into his mouth for him with his other hand.

"I was in that hole a day longer than you. Had I not been rescued there was a high possibility it would've happened. Cobweb had told me that all of the servants lose their names eventually." It's just they seemed functional. They thrived even if starved down in the Underbelly. The skeleton's case was different. It didn't feel the same.