Note: To celebrate hitting 1,000 posts about polyamory, I’m taking a break next week and answering any and all questions on other topics. You can submit your non-polyam-related questions (advice and otherwise) all this week!
Any advice for a couple exploring a re-open relationship, but the male party doesn't know how to find any femme/female partners and doesn't believe it's possible?
It’s entirely possible, otherwise there wouldn’t be any “male parties” in polyamorous relationships with “femme/female partners,” and there certainly are such people out there in the world, existing and dating each other and proving their own possibility. Read around about other people’s polyamorous success stories - the “happy” tag on the r/polyamory subreddit is a good start.
If he’s worried about his own personal prospects, he can also rest assured that many male parties worry about their chances with women, and such anxieties are not often accurate. The best way to assuage those fears is to just get out there in some polyam-friendly dating pools and be his best, most genuine self. The same advice applies to him as to every person trying to date: be a safe, healthy, and fun person.
The thing is, though, that it is never guaranteed that entering the dating pool instantly means someone falling, literally or figuratively, into your lap. He needs to be patient and accept that delays or setbacks are not referendums on his overall desirability - it can take months or longer for even the most awesome people to find compatible partners. If these type of thoughts - feeling convinced that he is undesirable or that his desires will never be possible - are part of a larger pattern or are coming from a place of serious insecurity or negative self-esteem, I strongly recommend some therapy focused on that.
His anxieties should not be a barrier to “the couple” exploring an open relationship - the other “party” should not be held back until their partner is completely assured that he will definitely find someone to date immediately upon seeking one, because those anxieties are not rational, nor are they his partner’s fault or responsibility. The best way to prove these concerns wrong is to get out there and try, and start realizing that this “it’s not possible” mindset is rigid and false, and that the reality is more complex and flexible. He may find that there are polyamorous women interested in him. He may find that his partner finds someone before he does, or that he takes some time and effort to find a partner, and that these circumstances are entirely survivable.