You should close the door for conversations like that. You never know who might be listening in.
Listen-in Sentence Examples
He wanted to listen in when she talked to Skippy in case he got out of line, so hurried downstairs.
You can also pick up an audio guide inside the Colosseum, or just wander near other tour groups and listen in to pieces of their speech.
When placing such a call, the couple should both be on the line if possible and arrange a time to call when both their parents (or grandparents or numerous friends) can listen in as well.
Viewers not only get the opportunity to peek into some of the most posh homes with the most spectacular views, but they also get to listen in as the agents broker these deals and interact with other agents.
Humans brave enough to enter a fairy mound can listen in on fairy conversations, but they do so at their own risk as it could cost them their lives.