Justin Timberlake believes that Kevin Federline is “gross,�?

Britney Spears’ ex-boyfriend reportedly does not approve of her rapping hustband Kevin Federline. In fact, Justin Timberlake believes that Kevin Federline is “gross,�? according to Star magazine.

“He thinks Kevin is gross, and there’s not much that would change his mind about that,�? a source told the tab. “He says that they [Spears and Timberlake] had a lot of great years together, and he’s pretty sad at how things turned out for her.�?

In mid-January, Justin Timberlake, reportedly telephoned his Spears to find out whether she was happy,Star Magazine reported at the time."Justin asked pointblank, 'Are you happy?'" a source close to both singers told Star. "Britney paused for a few seconds, sighed and said, 'Sometimes.... You know how it is.'" "Actually, no, I don't know!" responded Justin. The source said, "Justin told Brit that if she's not happy in her marriage, she needs to get out — for herself and for the baby!" (Britney and Kevin's rep says they "are great.")

Timberlake apparently hasn’t ruled out the possibility of reuniting with Spears - professionally, that is reports MSNBC.

“I’ll bet if Britney wanted Justin to help her put together a comeback record, he’d jump at the chance,�? says the source. “He’s someone who never backs down from an artistic challenge, and he’s said that he’d love to see Britney redeem herself through music — even if he has to give her a push.�?