Honestly Sylkie is a caricature of everything wrong with a lot of (canon) MCU romances. The MCU has this bizarre desire to add a seuxal subtext to literally every m/f relationship, even if it makes sense or not.
Like Steve and Sharon. Objectively a fine pairing in the comics. But in the MCU? It’s so gross. If we are to believe that Steve was always there and was always Peggy’s husband, then that means that he just kissed his niece. A child he would see born, grow up, and mature. HE KISSED HER.
This is the same weird relationships that color Sylvie and Loki. Calling her Sylvie doesn’t make them any less related. They have the same parents. They have the same DNA, bloodlines, and lives. They are more than related. It’s gross on every level.
Nat and Bruce are another example. There was no need to add that romance. It was just the idea that Nat was existing near men which means she needed to have a romance with one of them. Even if he’s a lot older. Even if they have no chemistry. Man + Woman = Romance. The lack of diversity creates a lazy writing environment. It’s assumed that the relationships makes sense, because he’s a man and she’s a woman. It doesn’t need to be more than that.
Sylkie is the exact same way. She’s female presenting, He’s male presenting, therefore it’s romantic. Not matter how they’re related.
It’s lazy, it’s gross, and I’m so over it.

