What is Nut-sac-dance?
When a squirrel dances and taps his feet to a little tune while his ball bag swings back and forth. or:
When you get overly excited about something but don't want to overtly express your joy.
zone-x/deez_nutz as an example
I was chillin when I found out I got the job. All night I was doing the nut-sac-dance!