Well, if you are Democratic Rep. Chris Carney of Pennsylvania you try to brush off the question. No matter whether it's a regular Joe asking him about it on the streets of Washington or whether it's a Republican inquiring while he's on the House floor.
In the video below, Carney says "I haven't seen it." In the one after that, he's asked to justify the spending item on the floor and chooses instead to yield to the Speaker.
On the street:
On the job: