The bucket's close enough at the time of eruption that it catches most if not all of the purged energon, and his hand remains firmly gripped on her shoulder even after she's done.

When he's sure she's not gonna purge anymore, he moves the bucket away from her so he can see just how much she purged. " . . . Hmm. Almost needed another one."

The tap interrupts before he has the time to answer Arcee.

"Um, yeah, considering she just like, purged her entire tank, I think we do."