It's over for Mary-Kate Olsen and Olivier Sarkozy.

While neither the 33-year-old designer nor the 50-year-old banker have publicly commented on the reason for their split, a source suggested the two

It's over for Mary-Kate Olsen and Olivier Sarkozy.

While neither the 33-year-old designer nor the 50-year-old banker have publicly commented on the reason for their split, a source suggested the two didn't see eye to eye when it came to the topic of children.

"Mary-Kate started coming around to the idea of having a baby and thinking about it seriously," an insider told E! News. "But Olivier was a closed book on that subject and was opposed to the idea. He felt like he had closed that chapter of his life and didn't want to go back. She didn't like the idea of not even being able to explore the possibility."

Sarkozy already has two children from his previous marriage to Charlotte Bernard.

However, a source suggested this wasn't Sarkozy and Olsen's only disagreement. An insider claimed Sarkozy is "very social," noting he "loves attending events and being with people," while Olsen is "more of a homebody and likes to be with the friends she is closest to."

"She doesn't need to be out on the social circuit," the source continued. "She's very focused on work and her brand. That's more of a priority and they weren't in line on that."