Joey Bada$$'s ex-fiancée, Serayah, is trying not to spill any more tea on their relationship -- a week after accusing him of cheating -- which is why there's now a mystery surrounding her engagement ring.

We caught up with Serayah outside of Craig's Tuesday night in West Hollywood, and we had to ask how she and Joey are doing after she dissed him in a frustrated post, claiming he's guilty of "repeated infidelity."

Well, a lot's changed in the last 10 days, because Serayah told us she and Joey are both "doing great" ... and they're "hoping for the best."

She then admits they're still talking ... and stays mum on whether she's returned her engagement ring. Notably, though, Serayah was not wearing it last night.

Reading between the lines ... it almost sounds like the pair are working on their issues -- though that would be surprising given the way she roasted him for his alleged infidelities.

ICYMI ... Serayah hopped on Instagram last week to say she had to choose her own happiness and break up with Joey. She also called him a "literal piece of s***" in a subsequent Instagram story.

Sources with direct knowledge later told us Serayah allegedly heard Joey and another woman talking behind her back right before their explosive split.

As Serayah says in our clip ... "grace and love" -- and maybe some forgiveness?