Being wrapped up in loved ones relationships

[ShwarmaQueen]

My mother and sister are both in yo-yo relationships with complete UAV's. Each time they break up, either because the other goes to jail, cheats, abuses, etc. they get mad and then go right back after the anger subsides. They say I don't understand. Maybe I don't, but I try. But I think I just can just see through the BS because I'm not sleeping with the violator. I'm letting myself get so wrapped up in their problems it's affecting my life! I've read Codependency No More but maybe I need a different approach. 

Suggestions?

[Sol_y_Paz]

this book

http://www.amazon.com/Boundaries-No-Inspirio-Zondervan-Miniature/dp/0762421029/ref=pd_sim_b_2

and this one

http://www.amazon.com/Boundaries-Workbook-When-Take-Control/dp/0310494818/ref=pd_sim_b_1