No, I don't ship them either. Don't come at me. But some people have made strong cases for Azriel and Morrigan being a rejected mating bond, and there's absolutely been hints at it within the series. There has, of course, always been an unspoken something between the two of them, but I think the biggest hint, though, is in the Azriel Bonus Chapter for ACoSF when Rhysand directly asks Azriel about Morrigan in the midst of a very, very heated discussion about what is and isn't appropriate to do with another man's mate. Why bring Morrigan into that conversation? What would her opinion matter unless Azriel was mated to her? Not that a romance would stem from this, but it's something to keep in mind (please Sarah the gays are begging you to give Mor a beautiful sapphic romance).
It's time for my daily cry. Another theory, and one that I think has some merit, is that Azriel was mated to Rhysand's younger sister. The one who died. Every time I see takes on this one I get emotional. And I know what some of you are thinking- mates have the potential to be driven insane by a rejected bond, much less the death of their mate. But I think that in both the case of Mor and Rhys' Unnamed Sister (that the fandom has lovingly dubbed, in most cases, Velaris) Azriel's proximity to family might ease the blow. He knows he has a purpose beyond the bond. But can you imagine the pain it might cause Azriel sometimes to see Rhys' eyes, if this were the case? I live for some good angst.
This feels like something Sarah has leaned towards, with the entire 'three sisters for three brothers' motif being a romantasy trope. And honestly? I love seeing Az be soft for her. They're sweet together. And it would open a door for us to explore at least one (if not two) rejected mating bond. Would I want that to happen to Lucien? Absolutely not. I love Lucien, I wish him the best. But it could also be a good kind of hurt. Although if that Bonus Chapter gives us anything to work on, it would be a difficult relationship to get started with Rhysand around.
I like this one as much if not more than Azrelain, personally. First of all we avoid the 'Brides for Brothers' trope, which is a massive win for Romantasy as a genre. But also there's a deep personal connection there, and chemistry that's undeniable. Azriel saved her life, and he's been super prevalent in her journey to recovery and self discovery. They bring the sweetness fans are fond of in Azrelain, but with an individuality that I honestly believe Azriel deserves.