Hell hath no fury like a country crossover scorned.

Taylor Swift took every imaginable precaution to avoid Harry Styles of One Direction at the 2013 NRJ Music Awards in Cannes, France last night (Jan. 26) ... but that doesn't mean she didn't send him another message to his face.

Swift made sure to hit the red carpet only after Styles and 1D were off of it, arriving 25 minutes after her former love of her life and future song inspiration was gone.

A source told Us Weekly, "It was very carefully timed so they didn't do the carpet at the same time. Taylor didn't do any backstage interviews and didn't use a dressing room -- she changed at the hotel because she didn't want to see Harry at any point ... things were timed to keep them apart and for it to not become a big media circus."

That should quash any Haylor reunion rumors and send One Direction ticket sales skyrocketing again.

Swift hit the stage to perform 'We Are Never Ever Getting Back Together,' the most mature breakup anthem like, ever, and sources say she looked directly at Styles, who was mere feet away, the whole time.

Also? Two words: Revenge dresses. For all of her humilation at the public scrutiny of her love life, the calculated Swift courts -- and tailors -- it like a pro.