Facebook acquaintance
Someone who chucks you a Facebook message every few weeks, but if you actually meet them, they’ll probably forget your name and ask if you’re related to someone else.
'Hey, how’s your mom?' 'She’s fine... why?' 'Oh, I thought you were her.'
'We were supposed to hang out last week... or was that last year?'
'You’re the one who said you’d come to my party... and you never did.'