figure of speech, a response expressing genuine or mock disbelief toward something admitted by the previous speaker
Felix: "I can''t meet up; I've got plans to watch Glee with my girlfriend."
Ben: "Who's the 'I' in that sentence?"
Felix: "Who's the...uh...me...it's me."
Ben: "Really?"
----
Dude: "I think I wanna volunteer in New Orleans this spring break."
Bro: "Who's the 'I' in that sentence?"
Dude: "You're right. We should just get drunk in Mexico again."
3👍 1👎