Rejoice, cynical women! It turns out most men do indeed seek relationships also, and the idea they'd rather have casual sex with with multiple women is a myth - or the "Casanova stereotype", as one Andrew P. Smiler puts it.
Author of Challenging Casanova: Beyond the Stereotype of the Promiscuous Young Male, the Wake Forrest University research psychologist writes that this stereotype "tells us that guys are primarily interested in sex, not relationships" which "contributes to the notion that guys are emotional clods who are incapable of connecting with their partners, because hey, they're just guys, and guys are only interested in sex."
Which, in turn, leads to the idea that "guys shouldn't be expected to achieve any type of 'real' emotional intimacy with their partners."
Those of us in, or who have ever been in, relationships with men will (hopefully) already know this to (generally) be the case. Still, research that exposes the folly of stereotypes tends to be a good thing, so hats off to Smiler.
In an interview with Salon (worth a read), the expert on teenage and adult masculine behaviour explains that: "It's actually a minority of guys who want multiple short-term partners - that even comes up in the evolutionary research."