what does "belly up"mean?
Stoney shot out a hand. “I knew your grandpa—you got his eyes. We had some adventures together back a ways. Some long ways.”
“Eli, why don’t you keep Stoney company while I get these drinks served?”
“Sure.” Due to the current lack of a stool, Eli leaned on the bar. “Can I buy you a drink?”
“Looks like I’ve got one here. Belly up, boy, and I’ll buy you one. You know your grandpa and I both had our eye on the same girl once upon a time.”