Shoot the breeze/bull
Definition 1 of 1
Pro Tip 1/3Social Context
Used during leisure time among friends or acquaintances, not in professional situations. 
At the family BBQ, we often shoot the breeze about old times.
Pro Tip 2/3No Agenda
Conversations are spontaneous without a specific topic or purpose. 
While fishing, they'd shoot the breeze, talking about everything and nothing.
Pro Tip 3/3Casual Relationships
Often indicates a friendly relationship, but not necessarily a close one. 
Sometimes I shoot the breeze with neighbors I barely know, just to be polite.