Cardi went on Instagram Live Friday to make it clear ... she's not divorcing Offset because of cheating, out-of-wedlock baby rumors, none of that ... she just got sick and tired of arguing.

Cardi was clear, saying, "I'm okay. I wanted to let y'all know I have not shed one tear." She did say in the past she's shed tears over media reports about Offset and their marriage, but no more ... "This time, I wasn't crying. You want to know why? The reason for my divorce is not because of none of that s*** that ever happened before. It's not because of cheating. I'm seeing people be like, 'Oh, he has a baby on the way.' That's a whole f***ing complete lie. That's the second time people are trying to pin babies over here. No, that's bulls***."

So, as for the real reason for the breakup ... "I just got tired of f***ing arguing. I got tired of not seeing things eye to eye. When you feel like it's just not the same anymore, before you actually get cheated on, I'd rather just leave ... nothing crazy out of this world happened, sometimes people really do grow apart."

Cardi wasn't done, saying, "I been with this man for four years. I have a kid with this man, I have a household with this man… sometimes you’re just tired of the arguments and the build-up. You get tired sometimes and before something happens, you leave.”

She was incensed at media reports the divorce filing was a PR play to sell albums.