Dancing in a unitard with no music. Specifically in relation to a juice stand. In northern California, the juice dance is thought to be similar to a rain dance as it will 'bring the juice'.
Interviewer: What's your favourite drink?
Bruno Mars: Oh, you know, just this little thing I made up. It's a mixture of rum and ginerale. I call it... dancing juice.
When you at an event where an erotic performer covers themselves in water, milk etc. and then shakes it on the audience. This liquid not only contains what they soaked themselves in but also their DNA.
I was watching an erotic performer on valentine's pouring milk on herself in a kiddy pool and when she whipped her hair, her dancer juice got into my drink.