A common saying is that women are generally more attracted towards men who are already in a relationship, and this phenomena does seem to have its own place in popular culture that is not matched by a corresponding male preference for women who are already in a relationship.
From an intuitive viewpoint I think it would make sense from the woman's viewpoint in an system of information economics where the fact that a male is engaged in a successful relationship with another female, or several other females, might provide extra and positive information about the evolutionary value of the male.
But how about the possibility for a male to use the same trick?
Is there any empirical evidence for this behaviour at all either in humans or in other species, or is this just a cultural artefact in some human societies? If there is empirical support, is there a consensus on the plausible evolutionary pathways involved here?