The skeleton jumps back when Gongenzaka yells, under the assumption that there's no exceptions - that no one means them, too. But then he offers an exception after all, rather like the Ringmaster had with hauling the egg out in the first place, and it gets her to thinking.

"He might not want to come out any faster, with us here," the skeleton points out in a lowered voice. "After everything."

"Well... It is Sans," the goose shrugs it off, and shakes his head at Tyki. "Taking forever to wake up, it's so like him! But maybe the sweet aroma of food would do more... than lighting a fire under his ass?"

It's still not clear what the internet has to say on the topic of death eggs, or why fire is involved. Maybe it's something to do with phoenixes. They can ask Peridot some other time.