I thought I had heard everything in Creole but I learned today that "metye" means lesbian or homosexual. I thought it meant "career" or "trade". would asking "ki metye w?", as I've learned from one of your post, be the same as asking about sexual orientation?

No.  The term is “nan metye” which may mean “Having a homosexual relation with”.  It must be within context to be translated that way.

Haitian sometimes may say “M pa nan metye avè w.” I’m not sleeping with you

Or one could say , “De mesye sa yo nan metye.” - These two men are together.

Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words