Before I delve into Tellius for this series of posts on love 'n' stuff, let's talk about what makes canon gay, well, canon. In a series like Fire Emblem wherein a lot of canon het is left ambiguous and declarations of eternal togetherness rarely surface in the form of "I love you," how do we recognize same-sex relationships when we see them?
1) It fits the criteria used for het pairings in that canon.
Let's take Fire Emblem romance on its own terms. Example numero uno here would be the paired endings for Raven & Lucius and Lyn & Florina, which don't even pass as business partnerships like the Marcus/Merlinus ending does. Raven/Lucius and Lyn/Florina meet every single standard for a "canon het" pairing in FE7. Yes, the (translated) text speaks of "friendship" and not love. Yes, neither pairing gets married. Matthew/Serra doesn't mention love or marriage-- they could just be having "friends with benefits" consolation sex. Or he's perving on her. Rebecca/Wil speaks of friendship and not marriage even though they cement the "friendship" by having a child. The Vaida/Heath ending speaks of "support," not love or marriage. Meanwhile, while I can't verify endings for them at present, Heath/Legault and Eliwood/Hector exist on the same plane as, say, Sain/Priscilla or Hector/Serra, het pairings without joint endings nonetheless enjoy a fair amount of popularity and really can't be deemed "crack." So what's canon, then?
[And again, every single pairing in FE6 except Zealot/Juno and the Roy pairings get the same level of endorsement.]
And as far as Kaga-era games go, find the part where Elice and Merric get married in the game text. It ain't there. In official art, yes. In the artbook, yes. But it's not in the game text for FE1 or FE3. Standards for canonicity are a wee bit slippery in the early days, so what makes Gordin abandoning Altea and following Master Jeorge to Pales (which, if you read between the lines is precisely what he does) any less telling than Elice's implied wedding to Merric? Or Linde's implied crush on Merric? Or Catria's implied feelings Marth? Etc. And again, we're not talking the reboots here, so I don't care what FE12 did or didn't do with these couples. We'll deal with that mess later.
2) Making it "not gay" requires an absurd amount of hand-waving.
Marty's canon epithet is "The Man Whom Dadga Loved." Even if you don't like your muscle-bound yaoi daddies, that one's hard to get around. And if the character Marty were Dadga's young son while Tanya had been a female brigand dubbed "The Woman Whom Dagda Loved," nobody would be thinking twice about accepting that as romance. If you have to resort to a blatant double standard to make it not-gay, or claim that "loved" means something else in a canon that doesn't throw "love" around all that often, then maybe we're dealing with a case of... canon gay.
3) Potter Stewart Rule, aka, "I know it when I see it."
This is very dodgy ground, because we're dealing with interpretation here. We're dealing with "seems" and "maybe" and "possibly" and "sure looks that way," which is a much weaker argument than strict application of #1 or #2. Or worse, we're dealing with "and what the hell was THAT about?" And the example I'm going to use is something I've danced around repeatedly, in meta and 'fic both, because it enjoys basically zero support in fandom either Stateside or in Japan, at least as far as I can tell. But damned if it isn't there in the text.
CONVERSATION (Finn, Selphina)
[Mark: so in Chapter 9 of FE5, Finn encounters an old comrade he hasn't seen in ten years. Selphina is about nine or so years younger than Finn, which means she was in her teens the last time they met. Her husband, Glade, has been Finn's
"Sir Finn! It's good to see you again."
Selphina: "Have you forgotten me? I'm Selphina."
"Selphina? Count Dorias' daughter?"
"...Well... So this is that little girl with the braids..."
"Ten years can make a big difference. I'm now married to Glade."
"Glade? He's alive!? Where is he? I have to see him!"
"He's not here. He went to aid the people in Tahra..."
"Oh, I see... Too bad. I suppose it can't be helped if it's an order..."
*The following part ensues only if Leaf already spoke to Selphina*
"You seem to be more interested in Glade than me, Sir Finn. You haven't
changed at all... You were always cold towards women."
"Cold? I never intended to be..."
"Then why did you leave Lady Lachesis? You knew how sad she was..."
"...I don't know what you're talking about..."
"Yes, you do! But you act like you don't know at all. You're cruel, Sir
"Selphina, we've met after many years. We don't have to..."
"Oh... Yes, I'm sorry. We finally meet again, and I can't do anything but
shout at you..."
"No, it's all right. We'll talk about it later. Right now, we must fight."
"Yes, Sir Finn..."
Got that? In terms of "whoa, did I miss something here?" that's right up with some of the classic bits of Tellius innuendo... especially as we're dealing with the character with the most screen time in the entire Jugdral saga aside from the three Lords and their tacticians. And yet, since the "Lachesis love triangle" thing has had far more influence in fandom, I've yet to see anyone take this at face value-- humorously or otherwise . In the exhaustive FE5 playthrough over at Something Awful, OP Cake Attack highlighted this as "an interesting piece of characterization" but didn't elaborate. A longterm GameFaqs poster currently going by the title Wrk20 will ambush you with this conversation if you try to argue canonicity of Finn/Lachesis, but takes it to simply mean Finn is kind of a rat bastard toward the women in his life (something that doesn't really add up if you take his interactions with Evayle into account). Even the Japanese meta site Tara Palace, which presents the maintainer's personal case against Finn/Lachesis in fine detail, doesn't really go there from what I can tell.
So, where does Selphina's little rant fit into things? I'm perfectly comfortable with saying Finn is not actually into chicks, FE4 mechanics be damned, but there are a couple of reasons not to make the full parabolic leap into saying "'cause he's into dudes."
1) Selphina argues about trivial things and maybe we're not supposed to take her seriously. X-ref her argument with Glade over whether Leaf inherited Cuan's eyes or Ethlin's. While canon paints her in a positive light, she's something of a little yappy dog.
2) Per canon, Finn's been an emotional flat-liner since the fall of Lenster. If he didn't show sufficient interest in or appreciation for this fine, fine A-list woman, it could be part of a much broader anhedonia and lack of interest in anything not geopolitical. [This appears to be where Tara Palace is coming from.]
3) He does say Briggid was beautiful. Twice. So apparently back in Gen 1 days, before all the bad shit went down, he at least took note of A-list women. (This is not the place to discuss prevailing tastes in Jugdral).
In conclusion, this "interesting piece of characterization" is more than sufficient to run with in terms of fanfiction and the like, not to mention for semi-humorous meta, but I'd be leery of waving it as "canon gay" in a dead-serious, case-closed sense. (Though it would be a hell of a lot more significant in terms of overall FE canon than Robin'n'Grey or Dadga'n'Marty!) And these essays are nothing if not SRS BZNS, which is why I'm dragging my feet over the all-important issue of Ike, Soren, Heather, Tibarn'nReyson, and the rest of the Tellius crew.
But if you ask me when I've got my personal preference hat on and not my SRS BZNS, defense-of-canon hat on, I'm gonna invoke the ghost of Potter Stewart and say "Yup. Gay." And then ship him with Lachesis and/or Briggid anyway because I like trainwrecks and boy howdy do those go off the rails.