Cousins as love interests in a fantasy setting - too squicky?

I haven't read all the replies, but I think if it's established that first cousins as potential partners is normalised in your world, especially in noble circles, I don't personally see an issue with it. You could throw in a couple of lines about the nobility wanting to keep their blood lines pure, which, historically speaking, is totally plausible. There may still be a bit of a squick factor but I think so long as you offer reasonable explanation a reader could accept it.

If this post was talking incest I'd be squicked out, even in a fantasy setting, as I can't help but find incest squicky no matter what the context, but cousins... I think you can make it work. Equally, though, if it's easy enough to make them second cousins, that's probably your easiest option.

It doesn't bother me, but I'm originally from Sri Lanka, where first cousin marriage is legal. Two of my uncles married (and had children with) their first cousins.

Still, best to take into account how the majority of readers might react.

I'm sorry, but eeewwwwww. I'm just giving you my honest opinion when I say I think it's gross. I'm an older guy, so if your target audience is MG or YA my opinion may not matter. But damn ...

I think both SFF and YA are a bit more lenient with this kind of thing - think of GOT, where people have actively shipped related characters due to their chemistry, which is probably something that wouldn't happen in, say, a soap.

Equally, (SPOILERS AHEAD) the romantic aspect between two people who thought they were siblings made my skin crawl in The Mortal Instruments series as a teenager. It grossed me out, and makes me wonder how many people might've given up on the books at that aspect (I never did, but I'm a freak for completion).

However, I think cousins are a different matter culturally and genetically, and in your description of them meeting later on in life as well as their romance being short-lived I don't think it's too much of a stretch for any reader to either enjoy their romance - or just stick it out to the end.

Anything goes.

Like others have said, it's a thing. And it works. Maybe not for some people, but for a whole lot of others yeah, it does!! It worked for V.C. Andrews, and her characters were real close, real related siblings!! They even turned it into a movie (twice!), and the second time around they even made it so that the whole series was turned into several movies. Plus, most of her readers were teenagers at the time anyway, and I don't think it was marketed as YA at all. If I had to guess, her target audience (if they even had one), could have been more along the lines of young adult women (18-25?), or just adults in general. A lot of people who read them said a family member (women mostly) lent them the books.

So do whatever you want. If a simple nod to a distant, temporary romance between two biologically related people turns people off so much they can't even get to the next chapter where they break up or whatever, then your book was never meant for them. If they're interested enough in the rest of the story, characters, arcs, etc., etc., most readers will keep reading anyway. And then there are those who will like your pairing from the start and be heartbroken when it isn't endgame and stuff. So there you go.

Don't alter the story for the audience, it won't please everybody anyway, especially you. So just write it however you envisioned it and let the right audience find it and enjoy it.

I'm reading a fantasy trilogy right now where the protagonist's love interest is his cousin, albeit not a super close one. It is reasonably popular and well reviewed, so it appears that many readers besides me aren't put off by this.

Rather than defining exactly how they're related, you might say that A is a member of the main line of the family, whereas B is a member of a cadet branch of the family. You know they've got a common ancestor in there somewhere--- but the two branches of the family tree diverged in an unspecified way. Making sure they have different surnames is an extra step in creating mental distance between the two branches-- sort of like the Minamoto and the Taira amongst the seshū shinnōke. The heir to the seshū shinnōke household could theoretically be tapped to become Emperor in case of emergency to keep the line from going extinct, such as if there was no one desirable amongst the direct lineage. But all the rest of the seshū shinnōke members served as bureaucrats/religious/etc.