How would you react to an E2 who "smart mouths" you in formation?

Wall to Wall counciling.

Counseling session.... preferably in the tree line

Immediately inform him of his insubordination and remind him that this is not a choice. This is an order. CM on assignments and have soldier stand fast after dismissing the rest of the work detail. Remedial PT until supervisor is tired. E-2 mouthing off to an E-5 is unacceptable. There are ways to respectfully disagree without attempting to undermine someone in a place of authority. Mouthing off in formation is not it.

Push the earth, until Bragg starts to Move, Front Leaning Rest Position, Move!

This is actually pretty simple question. This person requires physical discipline. In the form of additional PT. Should that fail, six their options are extra duty, or reduction in rank, and forfeiture of pay, in other words an article 15.

Bust him back to E-1

Front leaning rest position along with the whole platoon till blood runs from there ears.

The word "they" ... meaning more than one, should be concerning!

I agree...Everyone needs to know he just cross the line. Never tolerate insubordination !

"Scold in Private, Praise in public" have said individual stand fast, continue on with daily formation responsibilities, dismiss formation. Pull E-2 aside along with another ranked Petty Officer. Inform Sailor that the third party is there to observe verbal counseling session. Begin to dig into the issue at hand and find out if an underlying factor (family issues, career issues,etc) is present. If no issue prepare three separate counseling chits. Disobeying lawful order, disrespect to Petty Officer, dereliction of duties and forward said sailor to DRB so the anchors can sort the issue or send said Sailor up the chain. A lot of people on here are completely blowing the fact that today if you raise your voice to some of the Sailors, or Marines, or whoever you are speaking to its an EO complaint and a career killer. Ink is heavier than verbal words on paper.