Sif is not Thor -- she does not betray stealth in favor of laughter. That is a tendency in her friend that has gotten them all trampled by hoards of bilgesnipe in the past.

Still, she approves heartily that Cho is doing with magic what Sif so keenly desires to do with her own sword: tear these cursed walls apart. The grin that she shoots Cho's way is likely the friendliest that the sorceress has ever seen her.

She moves through the hole swiftly, though. A cursory glance around to see that no enemies are waiting for them on the other side, and her gaze is trained back to those still waiting to cross.