Chothes folowing the body

Hello everybody from Adobe Commuity. 
I'm having some trouble to refine this new character that I just made. It has this coat tied around the waist that always get behing the leg when animating. It was supposed to follow the moviment of the leg when it goes backwards.

This is getting me crazy. I couldn't find a solution online and I have tried several methods like using magnets and I even created another invisible leg... nothing has worked so far. 

So I came here to see if anybody here can guive me some clarity. What do you think? There another option that I could try?

I really appreciate your attention, thank you!