Hilton's publicist declined to comment on the story.
However, one insider told UsMagazine.com, "They are broken up."
"It's sad, she cares about him a lot and thinks he's a great guy but they really hit a rough patch," the source added. "[Cy's] found it difficult to live his life with her in the spotlight and that's what caused their split. No drama, it's amicable, but things didn't work out."