The answer, of course, was that if Obi-Wan wanted water, he could be drinking free ALL! NIGHT! LONG!
(As it were.)
Loki's gaze, of course, was always quite good at assessing – things such as, for instance, the somewhat flu-ridden look of the man, and the complete lack of a giant black Sharpie'd X on his left hand, not to mention the lack of signature brown bottles.
What this meant, of course, was that Obi-Wan could get a screwdriver, hold the vodka, should he wish, still for free – but then, if he preferred to pretend that he was drinking harder stuff, and wanted to pay his way, Loki was going to let him.
"You could say that," Loki allowed, and offered his hand. "Loki. I'm afraid I don't think I caught your name online, before."