Aaron Rodgers ’ family feud has been making headlines for years — but the reason behind his estrangement with older brother Luke Rodgers has remained a mystery. Aaron, 40, reportedly had a falling-out with his parents, Ed and Darla Rodgers , while in a relationship with Olivia Munn . Aaron denied that Munn, whom he dated from 2014 to 2017, had anything to do with the rift in Ian O’Connor ’s new book, Out of the Darkness: The Mystery of Aaron Rodgers , which hit shelves on Tuesday, August 20.

The author also gave insight into why Aaron and Luke, 42, have been at odds since the 2010s. (Aaron and his youngest brother, Jordan Rodgers , had a falling-out around the same time , which Jordan, 35, hinted at during his time on The Bachelorette in 2016.) According to O’Connor, Luke and Aaron’s feud came to a head in May 2015 after Aaron committed to being the best man in his former college teammate and roommate Francis Blay-Miezah ’s wedding but allegedly pulled out the night before the ceremony.

Luke attended the wedding alongside his parents and later posted photos with hashtags seemingly pointed at Aaron’s absence. “#truefriendsshowup ..

. #wouldntmissitfortheworld ..

. #rememberwhereyoucamefrom,” Luke wrote alongside reception snaps, per the book. Aaron allegedly felt that Blay-Miezah “could and should have honored his request to not invite his family” to the ceremony.

The NFL quarterback argued in the book that his former University of California, Berkeley te.