The condition in which a person lives vicariously through themselves.
Guy 1 at party: Hey I heard Betty was going to be here! Have you seen her yet, I can't wait to meet her! She's so cray !
Guy 2 at party: Dude, she's been here all night. She's that sad looking girl sitting alone in the corner.
Guy 1 at party: What?! I thought she'd be dancing on a table by now from all her awesome FB and IG posts!
Guy 2 at party: Yeah, you'd think but she has a classic case of social media syndrome (SMS).