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

I would pull the E2 aside after formation and tell him either do what you are ordered to do, or face and article 15 for the first time and if repeated then go for charge of insubordination and courts martial after forwarding my report to my Commanding Officer. Either way he will be an example of what not to do when given orders to do work.

Tell him to report to your office, write him up for disrespect and make him a PVT. This kinder and gentler Army makes it hard to discipline Soldiers, your only course of action is to take his money and if it keeps going his career.

He would need to be squared away immediately and back when I was in, he would have experienced additional disciplinary action if this had occurred on prior occasions, there were a couple that just kept up the extreme public insubordination and both recieved " Tune Ups" from several sr members of the platoon , after which all the insubordination stopped and never occurred again

Smile at them and Say. Okay. I will give it to someone else. Then do not acknowledge that person until he notices. Then ignore him some more. He will get the message and never complain again. There is nothing like being left out. Horrible feeling.

I think Gunny in the Full Metal Jacket approach. Gets the point across of who is in-charge. He definitely didn't learn in Basic Training.

In basic in Ft. Bliss (Blister) there was a unit known as "MAU," or Military Adjustment Unit. This is where the troublesome privates went during basic to get their "heads and mind" right. In Europe there was CCF or Correctional Custody Facility where soldiers were sent who misbehaved during deployment. It's a totally different army now and it has gotten WAY to soft on new recruits. Fail to follow an order in a hostile situation and people can die end of story!!! Give them one chance and if they fail to comply give them a DD on their DD-214 and introduce them to the world and the work force. JMO!!

If a junior Private First Class told me a Senior Marine NCO with +5 years under my belt in my formation that he wouldn’t do the tasks that I had assigned him. I would immediately have him and his squad leader report to the rear of my formation at attention until I’m done with my formation. I would definitely correct his demeanor immediately after, then I’d inform his squad leader and that Marine PFC that he is responsible for making sure my assigned task to his junior PFC is understood and carried out and completed as ordered. Now I can’t say anything about the other branch of services, but In the Marine Corps we have NCO’S and sometimes Junior NCO’s that are Squad Leaders. Lance Corporals are usually the Fire Team Leaders. Experience plays a big part in how you react to the situation. I’ve been a Platoon Sergeant, Company Gunnery Sergeant, and a Platoon Commander during my career and I never had a situation that you brought up during my time. Senior Sergeants have much more important things to deal with than a Private First Class with less than a year in the Marine Corps.
Semper Fidelis! PO1 George Martin. Happy birthday to Our Sailors in the United States Navy.

Without going into detail, I would stomp a mudhole in his ass and wade it dry.

Depends on the witnesses.

It is time for their first write up. When they realize when they sign up, they sign up to go for the whole lot then they will have to shut up and put up. This is the army not a civilian job. A write up is better then an article 15 though.