After doing such a good job in keeping secret details about their relationship, Cameron Diaz and Justin Timberlake's romance is on the rocks, the couple being seen publicly fighting in a club.

The couple was spending a night out at Los Angeles' Spider Club, when Timberlake started to flirt with a 'curvy blonde', reports In Touch magazine.

The two lovers started to fight and it appears Cameron burst into tears and left the club alone. "The argument got so nasty that Cameron and Justin ended up leaving in separate cars," In Touch quoted a source as saying.

Both Diaz and Timberlake's spokespeople denied the alleged row.