He cocks his head to the side, placing his hands on his hips. "You... don't sound too happy about it, though."

He straightens up and moves as if to slap Finnick on the back - fortunately he thinks better of it and pulls his hand back. "C'mon, get excited! We're at a barbecue! Talking about punching bad guys!" As far as Ben is concerned, it doesn't get much better than this.