Selena Gomez was “blindsided” by her ex Justin Bieber’s surprise engagement to rebound girlfriend Hailey Baldwin — but she’s far from upset, a source close to the actress told RadarOnline.com exclusively.

“At first, Selena didn’t believe the news,” the source told RadarOnline.com, explaining that the engagement seemed so sudden and out of the blue to Bieber’s ex-girlfriend.

However, “she is not devastated by any means,” the source insisted. “She was the one to end it once and for all with him.”

“She thinks the whole thing is a joke, and knows it will never last.”

As RadarOnline.com previously reported, Bieber, 24, popped the question to model Baldwin, 21, after just one month of on-again dating. The couple previously dated in 2015.

Gomez, 25, and Bieber last broke up in March after a whopping eight years of on and off dating.

Despite his plans to wed Baldwin, the source claimed Bieber has contacted Gomez in recent months, long after their breakup.

“Selena ignores his texts and calls,” the source said. “She really has nothing to say to him, but wishes him and Hailey all the best.”

As news broke of her ex’s engagement, Gomez relaxed with assistant and best friend Theresa Mingus on a boat in New York City. The star was all smiles in a blue bikini.

Miles away in the Bahamas, Baldwin showed off her huge diamond sparkler with her on-again man.