You’re telling me!
Definition 1 of 1
Pro Tip 1/3Strong Agreement
Use when strongly agreeing with someone; it can convey shared frustration or annoyance. 
These instructions make no sense. - You’re telling me! I can't figure it out either.
Pro Tip 2/3Common Ground
It's a way to show you are in the same situation or share the same opinion as the speaker. 
This traffic is endless. - You’re telling me! I've been stuck here for an hour.
Pro Tip 3/3Emotional Support
It can be empathetic, showing you understand and feel what the speaker is experiencing. 
I'm so stressed about exams. - You’re telling me! We're all feeling the pressure.