Facebookin' it.
A human who lives on Facebook more than they live in the real world. They eat, sleep, and breathe Facebook.
'My friend is a Facebookin' it monster, they even posted a picture of their breakfast.'
'I see my cousin on Facebook every day, but I don't see them in real life.'
'My mom is a Facebookin' it beast, she posted 20 times today.'