Sit-com style homophobic and racist jokes don't suddenly become funny because you have some scifi euphamisms to hide your bigotry behind, especially if the characters making the bigoted joke are protagonists were supposed to agree with and think are pure cinnamon rolls above reproach.
Why are you, an author, making bigoted sitcom style jokes in 2025? Who in your audience do you think is going to laugh? Who is this for?
Why do you expect your audience to laugh at the thought of a character being embarrassed and shamed that their adopted Black sibling might be dating another Black person?
Why do you expect your audience to laugh at the thought of a character being embarrassed and shamed that their adopted trans sibling might be dating another trans person?
Why do you expect your audience to laugh at the thought of a character being embarrassed and shamed that their adopted gay sibling might be dating another gay person?
Why do you expect your audience to laugh at the thought of a character being embarrassed and shamed that their adopted robot sibling might be dating another robot?
Why do you expect your audience to laugh at the thought of a character being embarrassed and shamed that their adopted sentient-spaceship" sibling might be dating another sentient-spaceship?
When you're writing direct metaphors for Chattel Slavery and anti-Black racism, who, exactly, are you catering to when you include jokes that with the scifi euphemisms stripped away, are the literal racism at their core?
Why is the thought of two people who are enslaved by systematic oppression finding love together considered outrageously embarassing, shameful, and beyond the scope of any reasonable person?
Why do you find this joke hilarious and funny enough to have a Quirky Relatable Protagonist be the one to crack this joke?
Who, exactly, are you catering these kinds of jokes to about your own settings enslaved people?