In looking back at my novel-length fiction, I've noticed a trend that I seem to adopt with romantic subplots. (Sadly, this came about from looking at yet another novel and sighing, "I'd love to rewrite this." Blast my brain.)
I don't usually reach for love triangles, two men and one woman, but rather for a woman and three men ... which basically makes some kind of radial shape. It would be a pyramid if the men were also pursuing each other, I suppose.
Take Journal of the Dead, though there's no doubt even from early on that Rhiane is attached to Astennu, even though there's no possibility of the two ever being together physically (which is another trope I seem unduly fascinated with, the idea of lovers who can't ever consummate the relationship, but remain devoted). But there's a lot of interplay with both Gahir and Razentis, and the two couldn't be more different: the straight-laced, by-the-book guardsman, and the flippant, clever, vaguely irreverent diplomat.
The only thing they have in common is age: they're both significantly older than Rhiane. Now, the only character in Journal who has a specific age is the child, but you get a general feel for ranges from context. The main cue with Razentis is that when he interacts with Parashi (about a decade younger than Rhiane), there's no perceived impropriety due to the size of the age gap.
So I kind of have it in my head that Rhiane is on the cusp of thirty. Gahir is in his mid-forties. Razentis is in his early to mid-fifties.
Back to the love radial, I've been mulling over why the idea has such appeal. A small part of it is probably the rule of three ... that's always resonated really strongly with me, to the point where I've occasionally gotten dinked in short story writing for adhering so closely to it.
More importantly, though, is the dynamic of three versus two. When it's down to two people, there's no escaping that favoring one is slighting the other. It's not just about X, it's about not-Y. Adding a third participant reduces that element.
Even more significant, for me, is that love triangles seem to demand a certain amount of infidelity: you choose one, change your mind ... that's certainly the way far too many Hollywood love triangles play out. And this is just something that bothers / skeeves me. I don't care for emotional infidelity, either. Maybe it's down to philosophy - it almost cries for a thesis / antithesis / synthesis progression.
For me, it becomes less clear-cut with three. It's not an either / or, it's a multitude, infinitely more complex, and thus easier to stay back from the brink of making a promise and then breaking it. I'm not saying that these things can't be done for a triangle, but I'm not sure how successfully I can do them.
I've played the radial multiple different ways: there's no pattern as to who or how the female lead eventually ends up with. The only thing I haven't done is make my MC spoke rather than center ... which has obvious issues in a single POV scenario.