Christina Aguilera has no time for Tony Lucca. The Voice mentor has had an ongoing issue with the crooner since the show began. The tension struck a high chord during Monday's final performance show when Aguilera vocalized her disapproval of Lucca's song choice.

Christina Aguilera slammed Tony Lucca for performing a bluesy version of Jay-Z's 99 Problems. The pop star said that the lyrical connotation was a little derogatory towards women, but all in all I thought it was fun even though Lucca avoided using the word b---- during his performance.

Lucca's wife and daughter sat in the audience while he performed 99 Problems and the contestant was annoyed that Aguilera would choose that moment to reference something off-kilter.

How convenient that she waits the whole season to talk about all things classy, Lucca sniped of Aguilera. It's just so transparent at this point and pathetic, he told Us Weekly after Monday's show.

The Voice contestant's mentor, Maroon 5 frontman Adam Levine, stepped in to defend Lucca against Aguilera.

Just to clarify, just so you all know, the intent behind the song...we talked about this for hours. The '... ain't one' [lyric] is life getting at you, things bringing you down, Levine told the blonder mentor.

We're not referring to women, we're referring to everything...it's called a metaphor, he further reasoned.

But the Dirrty singer was not having it. She quickly used her own singer, Chris Mann, as a representation of how Lucca should act.

This is a real man, he respects women, she said.

When Lucca and Levine performed their duet, Aguilera spent the entire time texting on her phone, according to Us Weekly.

The two mentors eventually made up. Levine told the pop singer, I just want to say, I love you Christina. Then he opened his shirt to flash a T-shirt underneath with Team Xtina scrawled across the back in pink letters.

The same cannot be said about Christina Aguilera and Tony Lucca.

The two got off to a bad start from the very beginning. When this season of The Voice first started, Aguilera failed to remember the 36-year-old contestant from her time on the Mickey Mouse Club as a child. Later on, she called his performances one dimensional.

This is not the first time Aguilera has worn her emotions on her sleeve.

Justin Bieber made a guest appearance on NBC's The Voice on the April 17 show to debut the video for his new single, Boyfriend.

Before making his exit, Bieber went to say goodbye to mentors Blake Shelton, Cee-Lo Green, Adam Levine and Christina Aguilera. When bidding au revoir, Bieber shook hands with the male mentors and smiled. When he reached Ms. Aguilera, who put out her hand for a handshake, he gave her a peck on the cheek instead. Rather than looking starry-eyed, Christina Aguilera was caught giving him an icy stare.

Twitter blew up with users commenting on the chilly goodbye between Bieber and Aguilera.

Flipped to The Voice for a second & Justin Beiber was on. It sure seemed like Christina Aguilera despises him. + bonus points to Bieber LOL, wrote user Chuck Jacobson.

Christina Aguilera was so rude to Justin Bieber on #TheVoice last night! Watch her give him the cold shoulder, tweeted Hollywood Life.

Tony Lucca will go up against Juliet Simms, Chris Mann and Jermaine Paul for the winning title on Tuesday.