Blake Lively, left, and Justin Baldoni, right.Photo by TheStewartofNY/FilmMagic; Photo by Gotham/WireImage; Chelsea Jia Feng/BIBlake Lively filed a legal complaint against Justin Baldoni, her "It Ends With Us" costar and director.Lively accused Baldoni of sexual harassment and a retaliation campaign to damage her reputation.A PR expert said Baldoni, who denied the claims, has "an uphill battle" to try and win the lawsuit.Blake Lively's lawsuit accusing her "It Ends with Us" director and costar Justin Baldoni of sexual harassment and retaliation could end in a settlement or play out in a very public trial.