Amid rumors that Timberlake and Biel have split, his grandmother, Sadie Bomar, told a British magazine that despite his two-and-a-half-year relationship with the actress, the only thing JT is really committed to is his career.
"Jessica was keen to marry, but Justin isn't ready," Bomar told Closer earlier this month. "He's busy writing new material and he works hard to be successful -- he's really focused on that. As far as we're concerned, he's always been single.
"The girlfriends come and go, but we believe nothing has ever been serious," the grandmother added. "Justin does his own thing and he isn't ready to marry just yet."
It's unclear, though, whether he and Biel are finished just yet. Reps for Timberlake and Biel did not return requests for comment.
But E! gossip columnist Ted Casablanca said he believes the writing is on the wall.
"What I hear more from people who know them is that it's ending, that it's not going to work," he told ABCNews.com
It's a good thing too, Casablanca said.
"When he brought sexy back, it was a great moment for him. I wanted him to bring sexy back in his own personal life," he said. "Instead he brought blah back. They are one of the most anemic couples, and they are attractive people. But they've become two unattractive people. He's pale, he's pasty. She looks unhappy, she looks tense. They need to stop boring us to tears. Who cares if they are together or not.
"It's not working," Casablanca continued. "It's almost like they cancel each other out -- same age, same look. There's no heat. I don't think you're seeing as big of a dynamic as there was with Cameron."
As for the conflicting comments from Timberlake's family, Casablanca said: "This is obviously a man who needs to stop listening to his grandmother and mother. He's a well-known mama's boy."
That may be why it appears Timberlake is trying to give his relationship with Biel one more try.
On Sept. 30, US Weekly announced on the cover that the couple had called it quits and that Timberlake had ended the relationship a month earlier by telephone. Biel was said to be in "severe denial" about the breakup.
But that same, People magazine called the split talk premature, posting a photo of them holding hands during a Northern California getaway and citing a source who said: "They're together. They're not breaking up. Any time they spend time apart it's because they're working."
On Monday, Timberlake's mother did not exactly speak of Biel in the past tense when she was interviewed by E!
Asked what kind of woman she'd like to see with her son, Lynn Harless replied, "The one he's with now is awesome. He's found someone that'll golf with him, give him a hard time when he deserves it and stand up to him."
Presumably she meant Biel.
Timberlake's former NSYNC bandmate Chris Kirkpatrick also had good things to say about the two together.
"They're awesome. She's amazing. She's a real sweetheart," Kirkpatrick told People magazine last week. "He really cares about her. It's nice to see him happy."
On Tuesday, Timberlake and Biel were caught canoodling during a screening of "Where the Wild Things Are" in Vancouver.
The pair were "smooching quite a bit and they were definitely an affectionate couple. Justin sat with his arm around Jessica and they seemed to really enjoy the movie," a source at the movie told People.
With reports that the couple are "hot and cold" and "going through a rough patch," it remains to be seen if they will survive and whether Biel will join JT's illustrious group of past loves. Here are a few of them:
Stacy "Fergie" Ferguson
A little-known fact is that Ferguson, lead singer for the Black Eyed Peas, once dated Timberlake, before either of them hit the big time and BB -- before Britney.
"He was 16 and I was 23," she told Australia's Courier Mail. "It was before he got real heavy with Britney."
She told Britain's The Sun: "Although I didn't see him for many years, we've never had a serious falling out."
Once upon a time, they were music's golden couple: fellow Mouseketeers, aspiring pop stars and sweethearts.
"Britney grew up on my living room floor," Timberlake's mother Harless told a reporter. "I still love her to death. Justin and Britney were together 10 or 11 years, and from day one they had that chemistry between them."
The pair's high-profile relationship began in 1999 and ended abruptly in March 2002 amid tabloid speculation that Spears had an affair with her choreographer. Timberlake's song "Cry Me a River" is believed to be about the breakup.
Clearly, he still holds a special place in his heart for Spears. When she was spiraling out of control in 2007, he told Oprah Winfrey in an interview: "There's no ill will. I have nothing but love for her."
"We were teenagers," Timberlake continued. "And I think that's basically the best way to describe what happened to us."
"The columnist in me wants him to get back with Britney," Casablanca said. "But Britney's a lot of work. He would no longer look anemic, though. He could get a spray tan with her."
While Timberlake was rebounding from Spears, he reportedly hooked up with dancer-actress Jenna Dewan. The star of countless music videos and the dance drama "Step Up," Dewan has always denied she dated Timberlake.
When interviewed by Stuff magazine, she joked, "Who is that? He's a really good friend. He was and is an amazing person in my life."
Having shown a penchant for dating older women with Fergie, Timberlake began dating actress Cameron Diaz soon after they met at Nickelodeon's Kids' Choice Awards in April 2003.
Their relationship was well documented in photos of the couple at the beach, on the slopes and in the bleachers of Los Angeles Lakers games. Shortly after Diaz hosted "Saturday Night Live" in December 2006 and introduced Timberlake as the musical guest, the pair broke up.
"We have in fact, ended our romantic relationship and have done so mutually and as friends, with continued love and respect for one another," they announced in a joint statement in January 2007.
"I'm kind of sorry that one never worked out," said Casablanca, adding that the breakup was mutual but probably came more from Timberlake. "She's a doll and a catch," he said. "They were a hot couple. They had that Brangelina Redux. Enter Grandma and Ma not liking it, probably because it's too close to home. It's a shame they didn't just elope and say, 'Screw the family.' They were close to doing that."