My mum is taking advantage of my dad what to do?

ok my mum is really rude and disrespectful and my dad is upset by it but wont do anything she yells at him everyday over meaningless things and he has to put up with it, she is unemployed for 20 years which i see is acting like a freeloader and she disposes of her husbands property if she thinks serves no purpose i have to put up with it just like my dad. I suggested getting a divorce if thier not happy a few times but their both stubborn dont get me wrong the reason i think they should is i heard in exzact words "i dont love you" so whats the point of being together what should i do leave them be?????????