When someone brings up a topic when talking but immediately drops it and refuses to switch back to the dropped topic.
Conversational Blue Balls is when:

"Goodness, did you hear about what happened?"

"What happened?"

"Anyways, I'm gonna go."

"Wait, what happened?"

"Oh, don't worry about it."
by T.R.S. January 01, 2008
mugGet the Conversational Blue Ballsmug.