> he's honest with potential partners about being in an existing open relationship then the pool of women willing to date him evaporates
I believe already having one or more lovers makes you much more attractive since the fact that those people chose you (among others) means you are probably a good choice.
Also, it helps you be outcome-independent (i.e. you don't care as much about whether a girl you are talking to wants to have sex with you, since you already have other girls for that), which is thought to be at least part of what makes males attractive.
Of course you won't be able to have fulfilling and honest relationships with people that insist on monogamy, but the opposite is true as well.
I believe already having one or more lovers makes you much more attractive since the fact that those people chose you (among others) means you are probably a good choice.
Also, it helps you be outcome-independent (i.e. you don't care as much about whether a girl you are talking to wants to have sex with you, since you already have other girls for that), which is thought to be at least part of what makes males attractive.
Of course you won't be able to have fulfilling and honest relationships with people that insist on monogamy, but the opposite is true as well.