Tina Louise says her split with Brett Oppenheim was sparked by his brother's breakup with their "Selling Sunset" costar Chrishell Stause ... and turns out Brett and his twin have similar feelings that ended both relationships.
We got Tina at her Sugar Taco joint on Melrose and asked her what caused the breakup with Brett after about 8 months of dating.
Tina says things got to the point where she wanted to take the next step in the relationship, but Brett wasn't ready ... and starting a family was the sticking point.
As we reported ... Chrishell and Brett's brother, Jason, also broke up after months of dating ... and they said they also weren't aligned on the family issue. Turns out Jason's in lockstep with Brett.
It's interesting ... Tina says Chrishell and Jason's issues led her to start talking to Brett about the possibility of having kids, and that's what eventually led to them going their separate ways.
Like Chrishell and Jason, Tina says she will remain friends with Brett despite breaking up ... and if you don't believe her, just listen to her Christmas plans.