Mr. Church (Bruce Willis), brings the Expendables back again for a mission but the mission goes bad when one of the guys is murdered. The Expendables decide they don't like that and go on a mission of violence and revenge. And when things are turned against them from time-to-time, Chuck Norris randomly shows up to save the day (would you have it any other way.
This is pretty much Expendables 1, with a little more action and the addition of Chuck and "The Muscles from Brussels", Jean-Claude Van Damme. And if your lady friend objects, tell her that Gale from the Hunger Games is in it. Just don't tell her that he dies.