The custody battle between Usher and his ex Tameka continues to get more and more nasty. Today the singer testified about an insane fight that happened between the two…adding in every gritty detail. Messy! Get the 411 below.

Marisa Mendez

Usher took the stand in his ongoing child custody trial with his ex, and under questioning by his attorney, revealed how Tameka once went ballistic and “wanted to fight” … when he showed up at her house with his new sidepiece.

Ush testified Tameka walked to his car and said, “I’m gonna kick your ass. Bitch get out of the car. How dare you bring this woman into my subdivision in my house?”

He added, “She continued to spit. At this point she pulled the door open, tried to swing at her.”

Usher claims he had to get out of the car and block Tameka … who then hit him. Usher said he pleaded with Tameka to calm down, but claims “she threw a plate of food at the car” … as he fled the situation.

You gotta hear Usher describe the intense showdown — and remember, Tameka previously testified she once told the gf, “I will f**k you up.”

tmz