The rapper was unfiltered this weekend as he shared his thoughts on the whole situation -- namely, how he appears to perceive Jada and Will Smith's relationship ... and he seems to be on Will's side, saying Jada's been doing him dirty without getting too specific.

While it's unclear what exactly he's referring to when he says she's "out of pocket," there are many possibilities ... including a recently resurfaced 'Red Table Talk' clip in which she says she didn't really want to get married to Will, with her hubby sitting right there.

It's about as awkward as it sounds ... even though WS himself doesn't seem to be too bothered by the convo, as he joins in and also reminisces on those early days.

Still, it's just one of many clips that have surfaced in the past couple weeks that some point to as proof that their relationship is ... sorta strange, and maybe even a little toxic. At least from the outside looking in, anyway. And Kodak, too, thinks he senses some choppy waters.

That's exactly why he says Jada doesn't deserve a good guy like Will, but rather ... should be with him instead. His rationale isn't totally laid out -- but he invokes Pac to make his point.

KB says Pac wasn't "all the way gangster" his whole life ... bringing up the fact that Tupac went to a performing arts school in his early days. On the flip side, Kodak seems to think he's more thugged out than Tupac, and perhaps a better fit for her than Will might be.