@KadanFabrics She doesn't want it to stop. If she did, she would have already. She's enjoying it too much to stop. She wants her husband to catch them because she can't stop.
If your husband catches you fucking your cousin, he'll probably beat him up and MOST likely divorce you. Good luck!
@TrendhashtagsTv The only thing you can do is to be honest with yourself and talk to your sister, and tell her the truth. Tell her everything. Don't change/skip a thing to make yourself look good. She will see that the men she attracts are clearly bad for her.