Degenerate Dancers

Okay here is a second attempt for the dancers problem:

On a stage there are three groups of dancers, holding hands like this:

Now, they intend to stand in a queue where everyone in each group stands in a row, like this:

A dancer is happy if not more than one of the partners with whom he or she was holding hands is standing behind him in the queue.

Which group of dancers could possibly form a queue such that everyone in the group is happy?