I’ve seen Gorou x Kazuha and Gorou x Itto but I raise you Gorou dating both Kazuha and Itto.
Gorou and Itto already dating eachother before the resistance starts. They’re in a romantic relationship when Gorou goes away to fight and they write letters to each other and occasionally see eachother in person if Itto makes the trip up to see his boyfriend on Watatsumi Island.
But when Kazuha flees from Inazuma he makes a stop at Watatsumi Island. He heard the resistance was stationed there and if anyone could help him get out it would be them.
Gorou and Kazuha also already know each other. They’ve seen each other on occasion and have only talked once or twice but they do know each other. However when Kazuha comes to the island they get to know each other more and they fall for each other.
Just before Kazuha leaves Gorou sends Itto a letter and they talk about Gorou’s love for both Itto and Kazuha and Itto says he doesn’t mind if Gorou dates both him and Kazuha. So just as Kazuha is about to leave for Liyue with Beidou and the Crux, Gorou tells him how he feels.
They start “dating” as well. I say “dating” because Kazuha kind of isn’t there but they promise that when Kazuha can return or it is safe for him to keep closer contact with Gorou he will do so and as he boards the ship he presses a kiss onto Gorou’s lips.
When Kazuha returns to Inazuma and stays on Watatsumi Island whilst they plan their final attack Itto joins them and they all start talking. Kazuha is fine with Gorou also dating Itto and Itto is fine with Gorou also dating Kazuha. They themselves have no romantic spark between them but they become pretty good friends.
And that is how Gorou got together with his two boyfriends.
