How do you explain Sad or Sado to a none English speaker?

So saddo meaning a critical pathetic comment. Regarding someone who may be socially innept or weird. Example “avoid that guy Kids, what a saddo”

Or in a positive tone to a friend who has an odd quirk or hobby that they are really interested in.”you’re do sad”, reply, “I know, I can’t help it”

Or self deprecating, “I’ve made you a mix tape, I know, I’m sad lol”

All three are describing your self has pathetic but trying to explain this to a non native speaker.

Any tips?