Mariah Carey rants about Nick's betrayal during embarrassing concert in Japan.

The singer is going through some tough time following her separation from her husband Nick Cannon and she's said to be in an emotionally fragile state. Mariah has been silent about her failed marriage until now.While performing a cover of the Billie Holiday hit Don't Explain on Saturday night, the 44-year-old added her own very angry line.

In a recording of the performance posted on YouTube by fan Roy Fernando the star can be heard singing, 'I know you cheated motherf***er!' around four and half minutes into the song.

Divorce is hard road for anyone and if changing her lyrics like Bey wasn't bad enough,her overall performance at her Tokyo concert left her fans angry and upset.

Kicking off her Elusive Chanteuse World Tour, the Hero singer was lambasted by fans online after her show, claiming she had struggled to perform many of her songs and her famed voice was not what it used to be.During her performance for The song  "We Belong Together,", the hitmaker struggled with her microphone with the large butterfly decal detaching from the mic.

She attempted to continue uninterrupted with the song, though halted saying, 'Wait a minute. I can't go on.'  

Her performance was said to be quite appalling with the singer struggling to remember the lines to her song,singing off key and left the audience shocked.

She may going through the divorce blues and not yet ready for a show. Nick Cannon celebrated his birthday last week Thursday  and the television host revealed that a new religious inspired design now adorns his back covering up the large tattoo of his estranged wife's name that he got as wedding gift to his partner in 2008,which he displayed to guests by stripping off his shirt. See the video of Mariah singing below.