"She loves him and cares for him, but she's just not into him in that way anymore," a Lopez friend told OK! Weekly in its April 7 issue. "JLo is bored with Casper. She has a pattern of loving and leaving."
Lopez, 44, has reportedly been shopping around for a new place for Smart, 27, to live so he'll move out of the Hidden Hills home they share in California.
"This is her way of letting him down easy and taking care of him before she ends it," added the friend.
Lopez and Smart began dating in November 2011. While the couple's relationship has allegedly been shaky for a while, the friend told OK! there's no tension between them.
"Jennifer no longer seems too enthralled with Casper, and she wants some space," said the friend.
However, if Lopez follows through with the split, she most likely won't be single for long.
"I'm one of those people who does not like to be alone," Lopez told reporters at the TCA press tour in January, according to People. "I have no shame saying that at this point in my life. I think we have to own who we are."
Lopez has already been a bride three times and reportedly said she's not sure whether she'd ever walk down the aisle again although she believes in the institution of marriage.
The "I Luh Ya Papi" singer had wed and divorced Marc Anthony, Ojani Noa and Cris Judd. In between those marriages, she was known for having high-profile relationships with rapper Sean "Diddy" Combs and actor Ben Affleck, whom she had also been engaged to.
Lopez currently serves as a judge on Idol's thirteenth season alongside Keith Urban and Harry Connick Jr. She previously judged Seasons 10 and 11 but took the show's twelfth edition off last year to focus on her music career. During that time off, Lopez traveled for her first world tour with Smart, her mother and her five-year-old twins Emme and Max.