Facebook slagger
A Facebook Slagger is a person who thinks they're cool but never shows up when the rest of the Brochacho's are online and having the time of their lives on Facebook.
'He left the group chat right before the big meme showdown.'
'He turned his phone off when we were all laughing at the best meme ever.'
'He wasn’t online when we were arguing about who's the best meme king.'