Brody Jenner and Kaitlynn Carter split over "trust issues", as sources say they didn't have a "good foundation" for their romance.
The couple - who had been together for five years - have reportedly split just one year after they tied the knot, and sources now say the reason for their separation comes as they were both having difficulty trusting one another.
A source told E! News: "Brody and Kaitlynn have had issues since the start of their relationship. They did not have a good foundation for marriage because neither of them trusted one another."
At the time of their split earlier this week, it was also claimed the pair were never legally married, as they didn't make their union official.
Representatives for the pair, Scott Newman and Lindsay Maguire, said in a statement: "Brody Jenner and Kaitlynn Carter have decided to amicably separate. They love and respect one another, and know that this is the best decision for their relationship moving forward."
The split news comes after Brody, 35, recently said it "hurt" not having his father Caitlyn Jenner - who was formerly known as Bruce Jenner before undergoing gender reassignment - at his wedding.
He said: "Not having my dad at the wedding, it was a bummer.
"Honestly, it really did hurt and I would have loved to have her there, but she had better things to do. Apparently."
And Kaitlynn, 30, had explained Brody's father "cancelled" plans to be at the ceremony around "a week before".
She said: "Right before our wedding, Brody's dad cancelled on coming to the wedding, like a week before. Brody kind of brushed it off, but he has to have felt something. But he doesn't express it."