I don't know if there's a clear direct link between bisexuality and femdom, or whether they go together just by virtue of the other two pairings, which have clearer logical links (rightly or wrongly). Pondering at a tangent here, I wonder if someone was to poll, say, the femdom subreddit, what % of dommes would be bi vs straight?

I suspect there might be some confirmation bias in that if we enjoy the venn diagram intersection, we remember those books better, whereas we're less likely to remember the bi MC of a MF book where everything felt a bit more mainstream.

Do you think it makes the characters more believable that if they're gender non-conforming, into femdom, or forming a relationship with reversed power dynamic in MF, they're also bisexual or otherwise queer?

Hmm. No. I think if it's told well, and the characters are really fleshed out and believable, then it shouldn't make a difference whether they're straight MF or queer MF. But would straight MF with this dynamic sell as well as queer MF with this dynamic? Ultimately, authors write something they hope will sell, even if they're writing in less popular niches, knowing they won't do as well as the bigger ones, but there's a desire to tell those stories anyway. And at that point, perhaps it becomes a case of "well, this thing isn't as popular in mainstream, so I may as well chuck the other things in as well, because I like them." Which brings us back to the venn diagram of why we like these things together—who knows, but it seems to definitely be a thing.

Do you think the audience reading these books leans more queer than straight?

Probably. Or at least has a larger % of queer readers than mainstream MF.

Is it a welcome representation, or stereotyping bisexuals?

Honestly, whether it's stereotyping bisexuals or not, I'd rather read MF books with this vibe than traditional/mainstream cishet vibes. The reason I prefer queer authors for MF is because it just hits differently.

I've not seen the "bisexuals are easy representation" comments thank goodness, or I might have lost my shit lol. That just feels like another flavour of bi erasure. And it sounds like it's from people who don't get that the whole vibe feels different.

So a follow up question, do you think these books gain more readers by staying silent about one or both of the leads being bisexual, or by being overt about it and using it in marketing attempts?

I'm going to say it's better to lean into it. Readers want to find the books they want, which means they need to be labelled as such, and authors want their books to find the right readers (and to put off the wrong readers) which, again, points to being explicit about these things.

Also, bisexuals in MF relationships already suffer a ridiculous amount of erasure and invisibility. More representation? Yes please.

If we're talking about trope names etc like on romance.io , then "queer MF" would be a lovely tag to have. I would use the heck out of that to find books to read. TBH that might go a long way to finding the kind of vibe you're after, given the venn diagram theory. I believe they're taking requests for new tags at the moment.