Hazarding a guess that Jessica Biel isn't having a good day after Usmagazine.com came out with a report that her beau, Justin Timberlake, is "smitten" with co-star-of-the-moment Mila Kunis.

According to Us, "multiple sources" say the singer-actor has fallen hard for Kunis, a Ukrainian-born beauty probably best known for her work in "That '70s Show." She and Timberlake are fiming the flick "Friends With Benefits" in L.A.

Us senior editor Ian Drew dishes the dirt on this video clip: http://www.usmagazine.com/moviestvmusic/news/source-justin-timberlake-absolutely-obsessed--with-mila-kunis-2010169

The alleged up-and-down relationship of Biel and Timberlake has been fodder for the tabloids for months. Of course, true or not, all the anonymous speculating is great for sales.