Jennifer Lopez and Casper Smart [Photo/Agencies]

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Season 12 finale of 'American Idol'

Jennifer Lopez "doesn't know" if she will marry Casper Smart.

The 'American Idol' beauty admitted she isn't sure if she will walk down the aisle for a fourth time with the backing dancer, who she has been dating since splitting from husband Marc Anthony in 2011.

When asked about marriage at a press conference on Monday, she said: "I don't know. We'll see. I don't know.

"You know, I've always believed in that institution. I believe in it, but it is difficult. I've had my challenges, but at the same time I believe in love, and I think that is the main thing."

Jennifer - who took a year away from the 'American Idol' panel last year - also said 2013 was a pivotal time for her, where she learned a great deal about herself.

She added: "That was such a transformative year for me in so many ways. I had just divorced, I went on tour with the kids [five-year-old twins Max and Emme], and I left 'Idol'. All my security blankets were gone, and I was out there doing something I had never done before.

"[But] I was surrounded by love and family. I really grew. My goal was not to come out the other side and just survive it but grow as a human being as well as an artist, and I felt I did. I learned a lot."

Reports have suggested Jennifer, 44, and Casper, 26, have been drifting apart recently after a number of heated arguments.