Was he cheating?

I just got out of a relationship. And it's over a month now. And the reason why me and my fiancee broke up is confusing. He told me he isn't ready to get married or be in any relationship.Then later on it was about his finances. Then lately, it just started to dawn on me that he might be still inlove with his ex (who he still has constant communication with.. they hang out together because he says they're best friends!) My instincts tell me it was the latter. What do you think guys?