How Did Big Brother Turn into an Omega?

A certain interstellar pirate gets a righteous beatdown. When he wakes up, he discovers his sex has changed from A to O, temporarily. His underling is very worried that someone might do unspeakable things to his big brother, so the big brother gives him a bop on the nose and says, “Quit thinking about it. Keep this up and we'll both end up as space junk.”

Other notes:

1. They take turns on top, with an age gap. A steady, stingy big brother x a thoughtful, clingy little brother.

2. Looks like an AO pairing, but they're actually AA. Sweet romance with mutual feelings.

3. None of the main characters can really be called good people, which has a lot to do with the environments they grew up in.

Theme: You really ought to study hard and learn the basics