Coke Not My Cup of Tea

Alright, listen up, smoothbrain. This "joke" is playing on two meanings of the word "coke." One is the super addictive drug, and the other is Coca-Cola, a soda. The dude is saying he tried coke (the drug), but he didn't like it, comparing it to not being his "cup of tea," which is just a fancy way of saying he doesn't prefer it. You probably prefer sniffing glue, right?