Raina Williams tells TMZ that Ken recently flew from his home in Texas to go hang out with Gypsy in Louisiana amid her ongoing separation from Ryan Anderson -- and the reason, we're told, is because he wanted to be there for support ... and serve as a rock for GRB.

Ken's mother says he told her he'd always be there for her, and even though they're not together anymore ... we're told Ken felt compelled to be with Gypsy during this hard time.

With that said, Raina insists that he is NOT romantic with Gypsy at the moment -- something People first reported -- and goes on to say Gypsy needs to close the book on Ryan before Ken can even consider getting back into the picture with her as a boyfriend. As she puts it to us ... Gypsy needs to get a divorce from Ryan first.

In terms of Ken's intentions ... Raina tells us that her son's motivations are pure -- whereas she feels Ryan is untrustworthy and simply doesn't care for her the way Ken does.

There's also this ... Raina gives us more backstory on why Ken and Gypsy split up in the first place. She says Ken wanted Gypsy to experience life outside of prison before locking her up in a marriage ... and felt it'd be better for her to do that without him in the picture. The two of them first met in 2018, and eventually got engaged in 2019 before he broke things off.

FWIW, Gypsy herself has said Ken dumped her after the Hulu show about her life aired -- apparently, he felt she was becoming too much of a celebrity in the wake of all that.

In any case, Raina tells us Ken is a good man ... and he still cares deeply for Gypsy. As for whether this will lead to an official rekindling ... time will tell, but so far -- it looks promising.