one man waltz
It is simply the act of masturbating.
Hey, I'm gunna go take a shower and do the one man waltz.
one-man waltz
The elegantly clumsy performance of standing up and stumbling, or, generally, standing as if one's feet were being shot at, while sufficiently drunk.
He'd had six scotches and soda while sitting down: upon standing, he performed a one-man waltz.