Need help with how to help cousin.

My cousin is with someone that likes to talk to other women on Kik or some other websites. She caught him once and said it was a mistake and he would never do it again. Well I found him on some website and started chatting with him. My cousin has no idea I had until I was sure it was him.which it was but she didn't want to know anything. She said she knew he still was and couldn't do anything about it. Also she had just had his baby about 4 months ago. Not only was was he taking to other women and probably jerking off to them while she was at school.he hadn't even had sex with her for a year now.I just don't understand why she would want to stay with him if she knows that he still tasks to women and flirts with them and talks dirty to them when he should be doing that with his girlfriend that he says he loves and the mother of his child. She says she loves him and don't want to be without him. He tried to tell her that he would get rid of his phone but I doubt that even happened. She blocked me and won't talk to me and I think it was because of him. Should I just let them be? And be here for her when she has had enough of him cheating. I consider talking and flirting with other girls like that cheating so does she. Which is why I don't understand why she is putting up with something like that. She was married to a man that used to chat with other men yes men.she gave him a few chances but he continued so she started seeing other men.she used to get tired of him not wanting to have sex with her and when he did he would go soft. But at least she got him to have sex with her once a week. Its been a whole year. I tried to at least get her to fuck other men.but she wouldn't. I sent her a vibrater to her grandma's house a while ago.lol I know she got it. What should I do?

Honestly, if she is willing to allow all of this BS, then let her do just that. I know you love her, but you are wasting your time. If SHE were on here asking for advice, I would tell her to leave him and never look back. But most people will not leave bad situations until their limits have been pushed too far. Your cousin sounds very much like a push over type of girl, so I am thinking she will tolerate this for a long time before making any changes.

Maybe you should just leave her alone.