Britney Spears' ex-boyfriend Justin Timberlake reportedly disapproves of her husband Kevin Federline and believes he is "gross," according to media reports. The singer is horrified by the turn Spears' life has taken professionally and personally - and believes Federline is to blame.

A source tells Star magazine, "He thinks Kevin is gross, and there's not much that would change his mind about that. He says they (Spears and Timberlake) had a lot of great years together, and he's pretty sad at how things have turned out for her."

Timberlake is reportedly baffled as to why Spears continues to stay with aspiring rapper Federline, whom he feels lacks talent. The source adds, "He's definitely not impressed with Kevin's show business aspirations, and he thinks the guy is more and more like a walking punch line. But because he and Britney don't talk much, there's not a lot he can do about it - other than watch what goes down between them like it's a slow-motion car wreck."

Although Timberlake doesn't hold Federline in high regard, he still has a soft-spot for his former girlfriend. According to the source, "If Britney wanted Justin to help her put together a comeback record, he'd jump at the chance. He's said he'd love to see Britney redeem herself through music."

(This news article provided by World Entertainment News Network)