Tinsley Mortimer didn’t show up to film “The Real Housewives of New York” Thursday night because she’s skipped town to be with her on-again boyfriend, Page Six has learned.

We’re told that her castmates believe that her unexpected absence means she’s quitting the show, but sources close to Mortimer say that’s “not black-and-white yet.”

Sources tell Page Six that Mortimer was due to be at the Eventi Hotel in Midtown to shoot with the rest of the cast, but pals of the former socialite say she’s in Chicago, where her boyfriend, Coupon Cabin founder Scott Kluth, lives.

We reported earlier this week that the tumultuous twosome were spotted at the Big Apple Circus together. We’re told that word on the “Housewives” set is that Kluth has bought an engagement ring for her. Apparently Kluth asked her to come back to his hometown with him.

Sources say this isn’t a storyline for the show, and that Mortimer — who was previously married to Topper Mortimer — is ready to put her personal life ahead of her responsibilities for the Bravo show, which she joined in 2016 after returning to the city from Palm Beach.

It hasn’t been decided whether she’s just taking some time off from the show, which is shooting its 12th season, or if she’s quitting for good to be with Kluth. Her castmates seem convinced that Mortimer’s quitting the show, but sources close to Mortimer insisted Friday morning that she’ll continue to be involved in the show in some way this season.

Reps didn’t immediately get back to us.