Cheating — lots of men do it. Not just on annoying, nagging girlfriends with a few too many extra pounds, either. Sometimes, for mysterious reasons, men cheat on beautiful and intelligent women who look like the perfect package to any outsider. Even more strange is their choice of mistresses. The men straying from their gorgeous gals often seem to choose dilapidated women well past their sell-by date to cheat with. From a one-time fling to a serial sex addict, or a beautiful younger woman versus a scary looking street hooker, a lot of these extra-marital activities make you wonder “what was he thinking?” Here are some of the hottest women to ever get cheated on.

Sienna Miller

Sienna Miller is a drop dead gorgeous model and actress who had a tumultuous and controversial marriage to actor Jude Law. Their relationship was under constant scrutiny from the tabloids after Law’s affair with the family nanny surfaced. Daisy Wright had a months-long affair with Law in Miller’s house, and although Wright says she was ‘swept off her feet’ by Law, she realizes that he was strictly using her for sex. Law encouraged Wright to have a threesome with him, and she kept a detailed diary of the whole affair. Law even tried to convince her to see him after the affair was discovered — and he had issued a public apology to Sienna. He was busted with his fling when one of the couple’s children discovered Law in bed with the younger woman and tattled to mommy.

The couple tried to work out their differences, but ultimately went their separate ways less than a year later.