Courtney Robertson was reportedly the one to end her relationship with former The Bachelor star Ben Flajnik.

"She ended it," a source told Us Weekly.

"Courtney was in love with Ben," another source added. "She put a lot of work into that relationship -- him, not so much."

Robertson reportedly returned her three-carat $80,000 engagement ring to the Neil Lane jewelry store in Los Angeles on Sunday. Flajnik told In Touch Weekly last week that under contract with ABC, he and Robertson would've had to maintain their relationship for two years in order for either individual to keep the ring. The couple only dated for about 10 months.

Robertson, a 28-year-old model from Santa Monica, CA, got engaged to Flajnik, a 29-year-old winemaker from Sonoma, CA, when he selected and proposed to her during The Bachelor's sixteenth-season final Rose Ceremony, which was filmed in November 2011 and aired in March.

The pair announced earlier this month they had decided to break up and end their engagement. In their split announcement, Robertson and Flajnik -- who had maintained a long-distance relationship the last ten months -- stated they had "grown apart" due to "distance, time apart, and our need to focus on our respective careers."

However, Flajnik subsequently stated the couple had "mutually" decided to call it quits after discovering they "weren't as similar as we thought" while Robertson has said she believes they would still be together if they had lived together.

According to an Us insider, Flajnik will "date again soon," as he's "approached by girls all the time!"

As for Robertson, she has apparently wasted no time finding a rebound. Last week, she was spotted making out with The Bachelorette runner-up Arie Luyendyk Jr. as they shared an intimate dinner at a restaurant in Phoenix, AZ.

"We're told they were all over each other the whole time," a source told TMZ.

Luyendyk, a 30-year-old professional race car driver from Phoenix, finished second on this summer's eighth edition of The Bachelorette when Emily Maynard decided to reject him in favor of fellow suitor Jef Holm.