Vacuous

As in:

To every timely and pointed question that Bernice put to him:

Why was the hood on the Malibu still warm when she went into the garage?
Why was he walking the hallway in his boxers, with his jeans folded in his arms?
Why was there a yellowish stain and the smell of curry on said jeans?
Where did the little tatoo of a mermaid on the back of his calf come from?
Why was eighty dollars missing from the house account?
Who was the mysterious caller at 8:28, the night before, with the 253 area code?
Why was the sprinkler left on until 1 in the morning?

Roger’s answer was a little shrug of the shoulders, and a vacuous smile.