A definition that a rude middle/high schooler would give you. Grants a high probability of getting punched in the nuts and make you reflect life decisions.
Who Asked is commonly used in pointless internet arguments when the opponent runs out of meaningful things to say, often times this is an addition of weakness.
Greg: my grandmother died
George: Who?
Greg: My Grandmother-
George: WHO ASKED
The greatest insult to ever exist. Nothing but brute force can combat it
If you are really proud of something you did, or want to share a fact and someone says "Who asked?" You can't say anything back to that. It puts you in this weird spot where you can't say anything else. Next time someone says "who asked" to you, kick their ass. If someone insults you, say "who asked" and prepare yourself.
Tim: "ur shoes look like shit"
Mark: "Who asked"
Tim: *pulls out gun"