Meaning/Usage: To be informed about everything regarding that subject

Explanation: "Loop" is a cycle or a continual circular motion. When you are not in the circle, then you don't know what is going on. So being in the loop is indicating that you are aware of the situation. Being kept in the loop is asking someone to keep you informed about what is happening.

"I really want to know what happens so keep me in the loop."
"Keep me in the loop so I'm included."
"Thanks for the update. Keep me in the loop."

A. "I am meeting with my boss tomorrow about the presentation."
B. "Keep me in the loop and let me know what he says."
A. "Ok, I will let you know."

Other Common Sentences

"Keep me informed."
"Make sure I am included."