Jessica Biel "Has the Power" in Justin Timberlake Relationship

Jessica Biel "Has the Power" in Justin Timberlake Relationship

She's got the power!

When Justin Timberlake and Jessica Biel reconciled in July after a five-month split, friends assumed this time they'd marry. (The couple have been dating on and of for nearly five years.)

And a source tells Us Weekly it'll be Biel, 29, who decides: "Justin thinks marriage would hurt his career, but if Jessica threatened to leave, he'd do it," the source says of the In Time actor, 30.

The pal adds that New Year's Eve actress Biel (who took Timberlake back after he cheated) now "has the power" in the relationship.

PHOTOS: Justin's many women

Find out much more about the possibility of a Biel-Timberlake wedding in this week's Hot Stuff video, as told by Us Weekly Senior Editor Ian Drew.

Also in the roundup: new info on Jennifer Lopez and Marc Anthony's clandestine hookup, Jessica Simpson's Weight Watchers deal, and more!

Watch the video now and tell Us: Should Justin and Jessica wed?