kulak misafiri olmak

Etymology
From.

Verb

 * 1)  to overhear
 * 2)  to eavesdrop " sarcastically and/or from the point of view of the eavesdropper designating eavesdropping as overhearing".

Usage notes
kulak kabartmak usually implies the listener is purposefully trying to hear the conversation of others. To is more often accidental.