Frank Sinatra
While Frank Sinatra was still married to his first wife, Nancy, he had an affair with Ava Gardner, who was also married at the time. In the end, Sinatra got a divorce from Nancy, and in 1951, he married Gardner. On the other hand, he was unfaithful to her, which led to the breakup of their marriage in 1957.

Robin Thicke
Paula Patton was already his wife when images emerged showing singer Robin Thicke in the company of another lady while they were out drinking. Because of the reflection in the mirror, Thicke’s hand could be seen resting on her buttocks. Not long after that, the couple made public their decision to split up. According to court documents from 2013 (Patton’s words), Thicke attempted to be disloyal on Valentine’s Day in the past, but he was unable to complete the act due to the impact that cocaine had on his performance.