San Antonio Spurs veteran Tim Duncan is in the middle of a messy divorce with his wife, Amy.  Amidst rumors of infidelity, a report from the Hollywood Street King suggests Amy's alleged affair was retaliation for Tim's longtime affair with a college friend.

Amy cheated on Tim with her fitness trainer, according to  Tim also supposedly knew about Amy's affair, but chose to remain quiet in hopes of keeping his own affair with his male college friend a secret and out of the media spotlight.

"Amy treated Tim like a b---- throughout their marriage because she knew he was f---ing his BFF," an anonymous source told Hollywood Street King (HSK).  "Tim knows Amy was cheating on him but he's willing to give her whatever she wants, because he doesn't want Amy to tell the world that he's bisexual."

HSK's sources said Duncan and the unidentified man, who lived together through Tim's college days at Wake Forest University, also shared the same house during Tim's first two years of marriage with Amy.  Tim eventually purchased the man a condo.

HSK, a gossip blog, is the only site so far to report Tim having an affair.  If the site's source is correct, it appears Amy's affair could be in response to Tim's own longtime infidelity. 

Amy filed for divorce on March 27, citing the marriage as "insupportable due to conflict and discord," according to TMZ.  Details about the divorce could remain sparse - HSK's source says Tim's camp is fighting to have a gag order placed on his wife, which would prohibit her from publicly discussing the divorce proceedings.

Neither Tim nor Amy, who have two children together from their 12-year marriage, has commented on the rumors.