The Bachelorette season 9 contestant Desiree Hartsock better find a suitor she's willing to spend the next two years with -- otherwise she'll have to give back that pricey engagement ring.

A source close to the hit ABC dating show revealed to Enstars that as part of each contestant's contract, if the romance fizzles before two years, they "are required" to return the bling.

"Any couple that doesn't stay together for two years has to return the ring to the show, so at this point only two couples actually still have the ring they were given on the show," the source revealed.

Those two couples are Trista and Ryan Sutter, who met on the first season of The Bachelorette, and newlyweds Ashley Hebert and J.P. Rosenbaum. The Sutters will celebrate their 10th wedding anniversary later this year.

Although The Bachelor and Bachelorette appear to be one the most romantic shows on TV, all ending in one epic rose ceremony, the on-screen romance doesn't always last off-screen. The franchise's relationship success rate is pretty low. Former couples including season 16 Bachelor Ben Flajnik and fiancée Courtney Robertson ended their engagement in early October 2012. Season 8 Bachelorette Emily Maynard and fiancé Jef Holm followed suit just one week later.

Season 17 Bachelor Sean Lowe starred in the franchise's 25th season and is still with Catherine Guidici, whom he proposed to on a season's finale. Guidici accepted the proposal and the 3.15 carat sparkling Neil Lane diamond engagement ring that Lowe presented her at the final rose ceremony in Thailand. Although the two have been speaking publicly about their wedding, only time will tell if the Dancing With the Stars alum will actually make it down the aisle.

The two, who have said they will tie the knot on TV, have not started any wedding planning yet.

"I was never that girl to think about wedding-day details," Giudici, a graphic designer from Seattle, said during an interview on Good Morning America. "We are thinking about having it in California and that's pretty much the extent of it at this point."

"We are in no rush," Lowe explained.

The couple has no problem with waiting. They made headlines in March when they revealed their personal decision to abstain from having sex until marriage. Lowe said he was surprised by the public's reaction to their intimate vow.

"I guess it's because it's so uncommon these days," Lowe said on the media response. "My faith has been the center of my life for a long time and it's the center of her life as well, and that's no secret. We are proud of that fact. We realize that it's viewed as kind of being weird these days, but we are not going to shy away from it. We are unapologetic."

ABC did not respond to our request for comment.

Tags: The Bachelorette 2013 Desiree Hartsock