My insane headcannon of the night is that Toro and Gwenny Lou eloped during the war (poss soon after Bucky died, when it's suddenly so much more real that they could loose each other at any time and hey if the government can find another guy who can set himself on fire or another gal who can shot energy from her hands command might just not bother to tell the other one what happened) but they don't tell anyone given the general attitudes at the time + high command already doesn't really like them two specifically. They never really told the other Invaders they were dating for similar reasons and once they're married Toro knows Jim will tell him off for jumping the gun like that so he just doesn't tell him. It's not like Toro could ever wear a ring anyway and Gwenny Lou wears hers more covertly (maybe on a necklace she can put under her costume). The only one who knows they're married is Davey bc he knew they were dating and those two can't pull anything past him. Jury's out if Bucky knew they were dating.
Anyways after the war they're both trying to get to the point they can break the news to their family and friends and Toro's planning to retire from superheroes and get a normal job so they can actually live together. But like they're also navigating the after math of WW2 and the end of the invaders (+ maybe very early v battalion) and then Toro just disappears for four years.
Gwenny Lou thinks he's dead ofc so when he turns back up she's started seeing someone else and then he can't tell her where he was or what happened and then the Torch dies and Toro's in no shape to be a husband. And like they've been married 10 years and never lived together, they're both grappling with problems they don't know how to or can't explain to one another, and they're just straight up different people then they were in their early 20s.
No one knew anyways so there's no point getting a divorce even through either of them would have legal grounds. (And I don't think either wants to go to a court of law and accuse the other of adultery or abandonment given the situation) So they just kinda agree it's over.