We finally know the root of their feud!

Bachelorette winner Jordan Rodgers doesn't speak with his NFL star brother Aaron Rodgers, and apparently it's because the reality star and his family can't stand Aaron's actress girlfriend Olivia Munn!

"[Munn] has a strong personality and every meeting she has had with them has gone badly," a source dished to Us Weekly about the Green Bay Packer's rift with his clan.

"The family says Aaron stopped talking to them. While Aaron says they don’t talk because his family doesn’t like Olivia," the source added.

The strained relationship was hinted at but never directly addressed on the ABC dating reality show, so when host Chris Harrison asked Jojo Fletcher about it on the After The Final Rose special, she continued to play coy. "It's the same situation that it's been, but it's not something that we... it's not the focus for us right now, it's about us," she explained while sidestepping the question.

And the truth comes out...