Flying all across the country
The first was that Mark frequently went across the nation for work, which meant he may be gone for many days, leaving Sara alone with their son and, eventually, their infant daughter. Sara was a full-time parent at the time, so she could take it, but missing Mark so frequently became too much for her.
Photos of a different nature
Sara was also unhappy with the type of photographs Mark was producing at the time. The majority of his tasks were very mundane, such as large athletic events or photoshoots with models. But some other photographic gigs were extremely different…