Somewhere in the history of man, we created the words “aunt” and “uncle”, thus saving ourselves from having to say “dad’s brother” or “mom’s sister” or whatnot.
For some reason we still use father-in-law, or mother-in-law, etc. I’m also getting sick of phrases like “girlfriend’s parents”.
Surely we can do better. Let’s save some syllables and make some new words. Any suggestions?

“quasirents”
3 syllables? No good.