To spy or not to spy?

Jack: two boys are stalking us Mom! they went around the back of the building withOUT their parents and then they spied on us!!!

Me: Nooooo!

Jack: Very sarcastic, Mom. This is exciting stuff! We can spy back on them and catch them red handed!

Me: Doing what?

Jack: How the heck should I know. They’re spying on US! Sheesh! You’re not even listening to me.