She has shown me pics of him on FB. She laughs about his looks and how she is shocked that I would think she would be attracted to someone like that.
I know I'm sounding like a broken record here, but that's a huge red flag, standard affair "script" right there!
I am going by what you have posted to us, and the way she is acting and the things that she has said. The biggest red flag is her staunch unwillingness to even work on the problem.
