They're drunk and think you're a beer.
There's a term I haven't heard in a long time. When I was a teenager in British Columbia "chug" was a derogatory term of Native Canadians. I haven't heard the word used that way in over 20 years.
i believe that was their attempt at chud, canniblistic humanoid underground dweller, in other words, they tried to insult you. unless im completely wrong, then by al means, enlighten me