My husband is having sex chats with his cousin

And this first cousin is MARRIED with her own kids. Here's a mail I just received, guys. She needs your advice urgently.

Hi Funso,

 
I never thought I'd be asking for the opinion of your blog readers, but shit happens.
I've been having issues recently with my hubby in a less than 2 years marriage, have been really really unhappy for sometime now and its all based on infidelity issues, but that is not the issue now. 

There was a funeral in his family recently, his cousins returned, including an older female cousin of his who is married with kids. After the funeral, she returned to her base, But she has been crushing on him (apparently her own hubby is always on the move, works with the media). The disgusting part is, my hubby seems to respond positively, they even sex chat. 

My question is, should I report this to his mum since the lady is my mother-inlaw's niece?