social butterfly
Someone who enjoys frequently mingling with other people at social events. Tom's always been something of a social butterfly, so we've never really worried about him making friends or finding his way in the world. She used to be quite the social butterfly, but no one has heard from Sarah in weeks.
social butterfly
A person who flits from event to event without a care in the world. This derogatory phrase is usually but not always applied to women who “live to party.” Going from one dinner party or ball or benefit to another, they are preoccupied with being the height of fashion and popularity. According to one wonderfully descriptive characterization, a social butterfly has a “brow unfurrowed by care or thought."