Chelsea Blackwell is staying tight-lipped on whether she's officially back with ex-fiancé Jimmy Presnell -- despite their recent hookup in Florida, she's not ready to publicly declare a romantic reunion.

The "Love is Blind" star -- who just appeared on the Season 6 reunion -- joined us Thursday on "TMZ Live," where she tried to play it cool when it comes to the subject of Jimmy.

While Chelsea says she's trying to keep the current status of her relationship under wraps ... she was beaming as she hinted at more information to come on ... perhaps on the "Love Is Blind: After the Altar" special. So yeah, she got the showbiz plug thing down pat.

She did confirm the 'LIB' reunion was filmed 3 weeks ago ... so a lot's clearly happened between now and then. Remember, we got video of her and Jimmy getting very cozy last week in Fort Lauderdale -- and Chelsea did spill some tea about why they were down there together.

She made a not-so-subtle reference to Jimmy's "party animal life" -- which might have been more of a dig at him than anything else.

During this 'LiB' season ... Jimmy's partying was a contentious topic for the couple, and definitely played a role in them breaking up before they even got to the altar.

That being said, Chelsea says she and Jimmy are in a good place now and enjoying each other's company -- unlike some of their other castmates.

Yeah, we're looking at you, Trevor!

She also reminded us she's got a day job as a flight attendant, and it's time to get back to her normal life ... outside of showbiz.

She'll be back on flights starting Friday, and is already anticipating some big changes when it comes to her interactions with passengers.