The bacon is lying shattered on Zack's plate, so he picks up the pieces and eats those. He knows that holding bacon is the way to go, but he was feeling stabby. That homicidal desire melts away to some degree when he sees he's managed to make Dean laugh.

"Was that your wish? Just to see your mother?" he asks Taylor, then adds the qualifier of "S'okay if you don't wanna talk about it." After all, he doesn't want to talk about his own fuck-up. It wouldn't be fair to press Taylor on her wish.

"'Kay," he nods meekly at Dean, pleased not to have to ask what shark week means. Thanks to Dean, Zack already has an understanding that physical form and function are not topics for public airing. Considering his numbers are a mystery to Taylor, then her marine life might be along similar lines.

Maybe he should... just close his mouth and keep it that way. Or grab another coffee. Give it something to do.