One of Vanderpump Rules ' longest lasting couples is no more— officially . In February, Brittany Cartwright shocked Bravo fans when she announced that she and Jax Taylor had separated after four years of marriage and nearly a decade together. "Yes, marriages in general are very hard and I've had a particularly rough year this past year," the Kentucky native shared on their When Reality Hits podcast.

"Jax and I are taking time apart and I made the decision to move into another home to take some space for the sake of my mental health." And now, Brittany has officially filed for divorce from Jax , E! News confirmed Aug. 27.

According to legal docs, Brittany—who shares 3-year-old son Cruz with the fellow reality star—cited irreconcilable differences as the reason for the split, which she dated as Jan. 24. Brittany is seeking primary legal and physical custody of Cruz.

As for what relationship problems ultimately forced Brittany to walk away from Jax? Many assumed it was cheating on Jax's part given his history of infidelity . Meanwhile, some of their Vanderpump Rules costars—including Scheana Shay and Lisa Vanderpump —have weighed in to give their opinions on what caused the split. However, Brittany making their breakup official with a divorce filing isn't totally a surprise to Bravo fans, who watched the exes' marriage crumble during season one of The Valley earlier this year.

Jax even recently sought in-patient treatment for mental health struggles after Brittany reve.