She is just unlucky. Slutty women are fun to live with.
Michael is probably not contented in life, a lot of rich people are not happy in relationships.
When Michael is singing to Laura's tune, he is probably escaping from the boring Parliament sessions (Remember his job is to keep order as Speaker) and the stress of MP job (facing the needy people like an untrained social worker).
Not many people are cut out to be politicians.
Maybe Michael should go to the gym to workout, it is better than having affairs. Then again, there will be some ladies at the gym perving at him and one thing can lead to the next.
I have seen some strange relationships and the one thing about relationships that is uncomprehensible to me, is when a mistress look like Camilla while the wife look like Princess Diana, and the man will go for Camilla.
Isn't money and beauty the ultimate replaceable measure of success?