Its just a saying that means..the person will pay for your first drink if your going to meet up and drink stuff. :) He will pay for the first drink you imbibe! :)
No it don't..doesn't Bruce! It means the guy pays for EVERYTHING!!! ;) Drink up on some expensive drinks! If its only the first drink he's paying for..make it EXPENSIVE!!!! ;) HAHA! I wouldn't do this, personally. I would get diet coke. ;) I don't drink a lot of stuff..perhaps a mixed drink..like one or two at the most. :)