Did their toxic onscreen relationship spill over into real life? They made a hit romantic drama together, but Blake Lively and her It Ends With Us costar and director, Justin Baldoni, seem to have no love lost between them.

Not only didn’t they pose together at the NYC premiere, but neither Blake, 37, nor Colleen Hoover, whose bestselling novel the movie is based on, follows him on Instagram (but he follows them). Adding more fuel to the fire? Blake, who’s a producer, revealed that she clashed with the filmmakers about using Lana Del Rey’s song “Cherry” and gushed that her husband, Ryan Reynolds, wrote the climactic scene. (The screenwriter, Christy Hall, said just “a few little flourishes” were added.)

For his part, Justin called Blake a “powerhouse” but admitted, “There’s always friction when you make a movie like this,” which “creates the beautiful art. Everything in life needs friction to grow.”

This isn’t the first time Blake has had tension with a costar over the years. She reportedly clashed with Anna Kendrick on the set of A Simple Favor. Anna, 39, played up their onscreen animosity by saying things like, “She seemed nice – little did I know,’ leading to talk of strife between the two. But it was all put to rest when they reunited to film the sequel earlier this year!

Meanwhile, on the set of Gossip Girl, “Blake and Leighton [Meester] were friendly but not friends,” executive producer Joshua Safran once dished. However, Leighton, 38, called rumors that they clashed offscreen “sexist.”