Why do people always have to make relationships about the assumption that they're gonna have kids together? Have none of you ever heard of Platonic (philosophic, spiritual) and/or non-procreational Erotic relationships (in common english "using an effing condem")? Plus, there's a lot more to six than just penetration, in case anyone is still living under a rock.
I think lizards are beautiful creatures (aesthetically), that doesn't make me a zoophile. I think Arwen is beautiful too (in the movie) as is Mirri in Magic: The Gathering. So, if an Argonian, Khajiit or Mer walked up to me and we talked, and we connected spiritually with the same language, the same interests, humor and more, then why shouldn't we be allowed to get together as see things through? If we can't have kids together, either because my spermcells aren't accepted by her eggcells or the conceiving of kids would produce hereditary diseases, misshapings or whatever (and no, I don't consider mixed breeds to be misshapen, unless they actually have features that limits their functioning and well being), then we simply make it our mission NOT to get offspring. I guess a condem would be hard to get in a medieval world though. Goodyear hasn't exactly been born yet, so we can forget about rubber lol.
Besides, with the rather grotesque interbreeding of various dog species in modern day society, much of which causes dogs to suffer and have a plethora of diseases and problems throughout their lives - it's like people are throwing bricks in a Glass house.
Furthermore, have none of you guys ever heard of asixual people? These are people who simply don't have six because they lack a sixuality, they don't get "turned on" by anything. TBH though, I think a lot of these boxes that people put eachother in, are based on the assumption that relationship is biological and anatomical, which it isn't. It's mostly psychological.
Sorry for the parts where I'm ranting a bit. Just ignore that