It means that someone dropped their phone while texting you.
I was texting with my girlfriend and she dropped here phone and wrote "Looet edr".
A girl who won’t stop fucking laughing all the god damn time. She attends Milton Academy and is a total bitch. She is so dumb it makes autistic kids smart. She wants to go to UNC, good luck getting in there retard. Your going to Alabama at best.
Guy 1: Look it EDR she is so pretty
Guy 2: Naw she’s so dumb and annoying I want her to get RKO’d
Guy 1: Agreed