Ah hahaha my friends bag me out about it all the time. I hold stubbies like that too. And large milkshake glasses. I mean anything really, sometimes even holding a pencil.
When I was a child, I learned that it was polite to hold your pinky up when drinking something. So I trained myself to always drink with my pinky up so that I wouldn't offend anybody. Now, it's a habit.
It's just something that my pink involuntarliy and somwhat automatically does. I can push my pink back down all I want, but it doesn't stay down and it just pricks up again. It happens with everything I drink and in any shape bottle/glass/cup. My friends and mom have asked why I dfo it many times, and the answer continues to be "I really don't know, I can't help it really."
It's just something I do o_o'