What is "bubble dance"

n. a solo dance similar to a fan dance except large balloons are used instead of fans

The bubble dance is an erotic dance made famous by Sally Rand in the 1930s. The dancer (sometimes naked) dances with a huge bubble placed between her body and the audience to make some interesting poses.

In Tex Avery's cartoon Hollywood Steps Out (1941) which depicted various Hollywood celebrities, a rotoscoped Rand performs her famous bubble dance onstage to an appreciative crowd. A grinning Peter Lorre caricature in the front row comments, "I haven't seen such a beautiful bubble since I was a child." The routine continues until the bubble is suddenly popped by Harpo Marx and his slingshot, with a surprised Rand (her nudity covered by a well-placed wooden barrel) reacting with shock. Rand is referred to as "Sally Strand" here.