Similar to the E-2 question, how would you react to a young 2LT who is being unprofessional with a strong sense of entitlement?

Since I am a COL I suspect this young Lieutenant would be hard pressed to take such a tone as this with me. However, let's say I observed him responding to someone else in that manner when they tried to correct him. I would pull him aside and explain to him how critical humility and a sense of servant leadership are to being a good soldier (and officer). I would further explain to him that if he joined the Army just to boost his ego, then he needs to separate from the service at the soonest opportunity, as it's not about him. I would also explain the damage he is doing to the relationship between the NCO/Enlisted Corps and the Officer Corps. If his attitude persisted then I would find out where he is from and contact his leadership for further action.

When I was a 2nd Lt and still as a 1rst Lt, it will be a cold day in hell that I can't learn something from an experienced NCO. Rank be damned, the rules apply to everyone and officers and NCO's should set the example.

I'd probably laugh at first.

Then, if he was serious, I'd say, "Sir, I'm sorry but no one outranks the regulations. Please adhere to AR 670-1."

If that didn't work, I'd get his name, his unit, and get in touch with the CSM of the next highest echelon he served under to handle it, because my theory is that if this random 2LT is walking around like this and has this attitude, then it's a command issue at his parent organization and someone should have caught this attitude and lack of bearing before I saw him in the PX. Either way, I'm sure once that CSM hears about it and passes it to the BC, the situation will be rectified.

Get his name and go to Division CSM

I would note his name and unit patch and pass the information up to the next higher officer in my chain of command. Then go on with minding my own bussiness

I say by your leave sir,.... and go on about my business.... and continue my own course and steer away from this... there are shitbirds and there's nothing you can do about it unless you have rank above them.... then and only then will something happen.... you must keep your composure and know your place... walk away.

2lt tells you rules do not apply then ball up your fist and punch him in the face and say I am glad to hear that ....

"Excuse me, Sir. I'm sure its an oversight on your part, put a statement like that is usually followed by a Court Martial." (or, dending on the time and place, a grenade.)

Smile, and carry on! Karma's a bitch!!

I would take him to a quiet, private place and discuss the behavior expected of an officer in the military and how his behavior fell short of the behavior expected of someone of his status.