Justin Baldoni is getting back to business after Blake Lively sued him for sexual harassment.

The “It Ends With Us” star and director was spotted in public Monday for the first time since Blake filed her explosive lawsuit against him.

Justin and his wife ventured out in Los Angeles a couple days before the holiday … dropping off their kids at a relative’s house before heading into an office meeting.

No smiles from Justin here as he faces some pretty serious allegations … as we first reported, Blake claims Justin created a hostile work environment on the movie set and things got so bad there was an all-hands-on-deck meeting.

Blake claims Justin wouldn’t shut up on set about his alleged previous “pornography addiction” or his sexual conquests … and she says worked with PR teams in a coordinated effort to destroy her reputation.

For his part, Justin’s legal team has said Blake was the real nightmare on set … accusing her of not showing up and refusing to promote the film.