Do the bride and groom sin by performing this custom, and do these beliefs lead to polytheism?

This act is abhorred by sound minds and pure instincts. Its ruling depends on the belief associated with it:

- If it is done without believing in its efficacy to make one spouse submissive to the other: There appears to be nothing that necessitates its prohibition.

- If it is done with the belief in its efficacy in that regard: Then it is forbidden, because there is no proof for this, neither in Sharia nor empirically. Believing in the causality of something that has not been proven to be a cause is forbidden, and some scholars may consider it a form of minor shirk.

The advice is to abandon such practices.