'No Disrespect': Justin Timberlake Alludes to Ex Britney Spears Cheating Before Singing 'Cry Me a River'

Justin Timberlake knows he "Can't Stop the Feeling!" but he's at least going to try.

The former *NSYNC frontman ever so slightly addressed recent backlash he's received after the release of his ex-girlfriend Britney Spears' tell-all memoir before performing his hit song "Cry Me a River" during an hour-long set at the invite-only opening night of Fontainebleau in Las Vegas on Wednesday, December 13.

"No disrespect," Timberlake told the packed crowd — which included his wife, Jessica Biel — as he started singing the 2002 hit initially released eight months after his breakup with Spears and believed to be about the Princess of Pop cheating on him.

Spears recently confessed the rumors of her infidelity were true, detailing her one-night affair with choreographer Wade Robson in her bombshell memoir, The Woman in Me, which hit shelves on Tuesday, October 24.

"We were out one night and we went to a Spanish bar," the "Toxic" singer wrote of cheating on Timberlake during their relationship — which lasted from 1999 to 2002. "We danced and danced. I made out with him that night."

Aside from "that one exception," the 42-year-old insisted she was otherwise faithful to the "Mirrors" singer, however, she claimed in her memoir: "There were a couple of times during our relationship when I knew Justin had cheated on me."

Elsewhere in her jaw-dropping book, Spears detailed how Timberlake's release of "Cry Me a River" made her feel — which further fueled fans' anger when he sang it on Wednesday night.

"I was shattered," the "Circus" hitmaker explained of the track, which was accompanied by a music video featuring her look-alike. "Everyone felt very sorry for him. And it shamed me. I felt there was no way at the time to tell my side of the story. I couldn't explain, because I knew no one would take my side once Justin had convinced the world of his version."

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"I don't think Justin realized the power he had in shaming me. I don't think he understands to this day," she noted.

Aside from both singers' infidelity, Spears and Timberlake's relationship faced other twists and turns — including a pregnancy and abortion the "Gimme More" vocalist claimed she didn't want to have.

"I loved Justin so much. I always expected us to have a family together one day. This would just be much earlier than I'd anticipated. But Justin definitely wasn't happy about the pregnancy. He said we weren't ready to have a baby in our lives, that we were way too young," Spears admitted in her memoir.

She further confessed: "I'm sure people will hate me for this, but I agreed not to have the baby. I don't know if that was the right decision. If it had been left up to me alone, I never would have done it. And yet Justin was so sure that he didn't want to be a father."