What a turn! Katherine and Joe Jackson are fighting each other in court ... right now.
Katherine's new lawyer, Adam Streisand, is arguing to the judge that Joe has no legal standing to object to John Branca and John McClain as executors, nor does he have any standing to object to the validity of the will.
Streisand is arguing since Michael Jackson cut Joe out of the will, he has no dog in this fight.
During the fight, Billie Jean Jackson -- you know -- just stood up and said that she's an heir so she'll object ... so Joe's got that going for him.