EXCLUSIVE: 'The Bachelorette' Kaitlyn Bristowe's Fiancé Shawn Booth Having A Tough Time Letting Go Of His Ex

Shawn Booth may have gotten down on one knee at the end of July and asked Kaitlyn Bristowe to be his wife, but little did The Bachelorette beauty know her soon-to-be fiancé was still calling his ex.

A source tells Star exclusively that Shawn likely had his longtime ex-girlfriend in mind during his proposal to Kaitlyn, 30, and that his words could have very well been influenced by his ongoing feelings for his ex. "Knowing that the person you are with is something you can't live without," Shawn said during the proposal.

In fact, claims the source, Shawn, 29, was desperately reaching out to his ex just days before The Bachelorette finale aired—which was long after his proposal had been filmed.

"Shawn and his ex dated on and off for six years," says the source. "Even after their 'official' breakup, I don't think he ever got over her."

In fact, the couple, who both attended Keene State College in New Hampshire, was even at one point discussing "eventually getting married and having kids together" while they were dating, the insider exclusively tells Star.

Eventually, says the source, "they couldn't agree on a permanent living situation. He was going back home to Connecticut, and she didn't want to move away from her family. They carried on a long-distance relationship for a while, until they finally called it quits in 2012." And the torch took a long time to blow out for him—if it ever did.

"He was still in touch with her this summer. But then he texted her the news that, in his words, he was 'technically' engaged to Kaitlyn—and his ex decided to end their communication," a spy exclusively tells Star.

Then, on the premiere night that Shawn asked for Kaitlyn to be his wife on The Bachelorette finale, "Shawn tried phoning his ex three times during the night," the source claims, "but she wouldn't take his calls."

Then, on the premiere night that Shawn asked for Kaitlyn to be his wife on The Bachelorette finale, "Shawn tried phoning his ex three times during the night," the source claims, "but she wouldn't take his calls."

Shawn's struggle with jealousy, his flirty behavior with other women, and even Kaitlyn's parents messy divorce in the past—pick up Star's new issue that hit newsstands on August 5 to read the full juicy feature!