Sources claim Jay Z suspects Beyonce of sleeping with her longtime bodyguard, look Julius De Boer, and is furious that she refuses to replace him…

From Star Magazine

“Jay definitely thinks that there was and may still be something romantic going on between Beyonce and Julius,” an insider tells Star of the hip-hop mogul, whose own rumored cheating was the reported cause of Solange’s attack. “He wanted to fire Julius last February, but Beyonce said, ‘Julius isn’t going anywhere.’”

Despite being subject to numerous cheating rumors himself, Jay is, nonetheless, “very jealous” of his wife’s friendship with Julius — and friends believe he may have a reason to be.

“They’ve spent a lot of time together behind closed doors,” the source explains. “He’s even stayed in her hotel room.”