Lorde celebrated her 18th birthday Friday in New Zealand with her boyfriend ... and their matching buns.
The young singer hit up a cafe in Auckland yesterday after officially becaming legal ... but we're guessing she probably didn't buy cigarettes and porn or go to the strip club.
Lorde's BF James Lowe -- who reportedly worked as her photographer before they started dating -- has said dating the famous singer has been a whirlwind from all the attention.
At least the dude's got a sweet ponytail.