Heavy Breather

We have one male patron that likes to call and talk to certain women that work in the library. He likes to keep them tied up on the phone asking tediously obnoxious questions just so he can listen to their voices and play with himself on the other side of the line. The ladies can hear him moaning and breathing heavy on the line but the guy just won't 'get off' and the ladies are too polite or too shocked to just hang up.