I think the main character and his wife were working in a school (This detail might be wrong). A slick guy got a job as their colleague at some point and he began undermining the husband until the typical betrayal stuff. After that, the husband started gambling and started making it big there. He found a girl who lived in Las Vegas (I think) along with her little brother OR son. He took to calling her his "alley cat", but I think it more meant that she was really protective of him or something.