Justin Timberlake is finally clearing up one of the longest-running theories about his music — and Britney Spears was not the muse this time.

While breaking down his catalog on a song-ranking video series the singer explained that "What Goes Around... Comes Around" grew out of a story a buddy shared about his own rough breakup. Timberlake says he asked that friend for permission before turning the saga into lyrics.

The pal signed off with a blunt blessing that ended with the exact phrase that became the title: "What goes around comes around." Timberlake remembered rushing off the phone because the idea had already landed. "I got it," he told his puzzled friend.

Written in about 20 minutes

Once the call ended he says the whole track came together in roughly 20 minutes.

For years fans assumed the 2006 single was aimed at his famous ex. Plenty of listeners treated it as a sequel to "Cry Me a River" — the 2002 smash widely read as his kiss-off to the pop princess.

One question still open

Timberlake did not offer the same clarity about "Cry Me a River." He has never confirmed one way or the other whether Britney sparked that song.

He did touch on it without naming anyone in his 2018 book "Hindsight: & All the Things I Can't See in Front of Me." There he described feeling scorned plus furious at the time and wrote that he finished the track in two hours without planning to write it at all.

More answers could be coming. Timberlake has a docuseries about his life on the way.