Best definition
You deserve it.

Dude, you fucked your girlfriend in your mom’s house, and the next morning your mom imitated your gf’s moans? YDI.
YDI: define #2
You Deserved It:

A term often used when commenting on FML’s. Meaning a person deserved exacly what they got.
Person 1) F My Life!!! I just hit my wrist against this wall and it broke!!!

Person 2) Dude…YDI. You are such a dick.
YDI: define #3
You deserve it…
You know what it is. Because YDI!
YDI: define #4
You Dumb Idiot
Him-I was drunk last night and was fighting the wall. I broke my wrist.

YDI: define #5
You Did It!
Joey: Mom, I passed the math exam!

Mom: Congratulations, YDI!