Madonna's court battle with Guy Ritchie over the custody of their son Rocco has yet to end. Somehow, the strain of the process reportedly caught up with the singer during her "Rebel Heart" concert in Nashville on Monday. Madonna was heard cussing about an ex and it's believed that she was talking about Ritchie.

Madonna's foul-mouth rant against Ritchie reportedly happened on stage. According to The Sun, the pop star responded to a fan's proposal and took aim at the director.

"I'm looking for a husband, not a c**t. I already married a c**t," she said.

Fans were believed to have been surprised to hear her cussing over her ex-husband. Her tirade also happened after she arrived to her show more than two hours late.

Madonna is said to be battling custody rights with Richie over their son Rocco. Ahead of her Nashville concert, she and "The Man from U.N.C.L.E." director appeared in a New York court before Christmas to settle parental rights over Rocco. The judge reportedly ordered Rocco to return home with Madonna. However, the teenager refused to be with Madonna in the U.S. and insisted to be with Ritchie's second family in the U.K.

According to The Sun, Rocco was very supportive of his mother's "Rebel Heart" tour. But in December, the 15-year old suddenly decided to live with his father in London.

Madonna's foul-mouth rant against Ritchie also came after she was accused of being drunk while performing at her Louisville concert. News.com.au claimed the 57-year-old arrived late for her 8 p.m. concert. She arrived at 10 p.m. and was suspected of being drunk that's why she was late for her show.

However, the pop legend took to social media to deny that she was drunk. Madonna also took a swipe at TMZ for initially giving false information.

"For those people who like to believe all they read i never drink and perform!!! My show is 2 hours and 15 minutes of non stop singing and dancing," she wrote on Instagram.

Madonna explained that during her Louisville concert, she joked about "doing a stand comedy act dressed as a clown and being able to drink alcohol." She wrote how it was interesting that society took whatever she said literally.

"That's what happens when people don't read books and get all information from TMZ," she wrote on her Instagram as a parting message.