There is something to be said about the Captain's internalised homophobia. It probably already has but I want to.
In Redding Weddy, we obviously see him burying the letter and rigging it to explode but that's all in the past. I want to focus on the present. When Fanny tells him about her attraction to someone, he tells her to "bury that emotion deep down and never let it show" and that "nothing good will come of it." This is obviously reflective of how he still views his own homosexuality as a source of shame.
However, in Perfect Day, he is fully accepting of Claire and Sam getting married. He actively helps set up the wedding and is proud of all involved when it goes successfully. This indicates that while he remains ashamed of his sexuality, this homophobia is exclusively internal and doesn't extend to others.
I may be going too in depth but to me, this shows that the Captain is quicker to judge himself than others. What is a moral failing for him is forgivable for another person.
If you want to go another step further, this can also be tied into the fact that the Captain is very autistic coded. Growing up nuerodivergent is an isolating and confusing experience, largely due to the fact that everything you do is percieved as wrong. You can say and do the exact same things as other people and yet still be told you're doing it wrong. Your tone of voice was rude, your body language makes you look uninterested, you're being wilfully ignorant but all the while, you don't know what you're doing wrong. I think this is where this trait comes from.
So in conclusion, the Captain is an autistic gay man with internalised homophobia and his experience growing up as an autistic person shaped his tendency to judge himself for things he forgives others for.
the fact that the captain watched two women get married in the same fucking room he died in because he dared to harbor affection for another man. like. the fact that all the contact they got was the shared warmth of their hands and a first name. and now here, almost 80 years later, two women are kissing and dancing and loving and getting married. and living. are you listening..
Sometimes the stars so perfectly align for me that today I saw my aunt who I never really see. She tells me she’s seen this show I might like, from the guys I’ve been obsessed with for like 14 or whatever many years. It’s Ghosts. I never wear this shirt because I love it and want to protect it. I just slowly lifted up my jumper to reveal a shirt with this pic on -
Cue my mum’s tired sigh, it’s been 14 years and she thought my MM obsession killed it off.
the tiny look of wonderment and hope when alison says "that's the other bride" and then the wariness and confusion, it's too good to be true, that can't be right. can it? and then she says "they're marrying each other" and you can almost see the breath of relief as his face lights up. you can literally sense the decades of fear and shame sliding off of him for a moment. he's safe and happy and it's such a beautiful achievement. progress. in the room where he died, heart giving out after keeping his deviant affection inside for so long. and now here they are, two beautiful young women, marrying each other, happy and together and alive. perfect day is the only episode of television that matters actually.