Different type of "hot dog" on wheels

Flashback...
I was working late with a co-worker. Everyone left for the day. I'm looking going through files totally focused on my project. She grabs something from her purse. I noticed her walking over to the end of my desk. I hear this winding sound and this thing zooms by and hits my stack of files. "Holy crap it's a penis on wheels". I was stunned for a moment and then we both started laughing. She grabbed it quickly and put it in her pocket. Just in case someone should walk in. It sure was a silence breaker.