I adored you Madly, Extravagantly, Absurdly.

The Blacks want to marry off their youngest child. He begs Sirius for help and tells him a secret: He is a man and would rather die than be forced to be anyone's wife. Panicked, Sirius arranges a marriage between his brother and his friend James Potter, knowing that Regulus can be the man he is in the English countryside in James' estate, which is a sort of safe haven for homosexual servants who are running from the law or are already convicted.

James wants to ensure Regulus' happiness, even at the expense of putting his life on hold for a while.
Regulus wants to ensure James doesn't fall into societal ruin because of him.
Sirius just wants to help.
And Remus is just a very tired butler who watches James and Regulus dance around their actual feelings (literally).

(Trans Reggie; set in the Victorian Age, 1890s. No horrible homophobia or transphobia depicted. Dysphoria is thematised. Other tags may be added)