"What has always been at the forefront of our relationship is love and care for one another," Demi, 24, captioned a sweet black-and-white photo of herself and Kristian, 27.
"Our priority is doing what is best for us. With a heavy heart full of love for one another we have decided it is best for us to take a step back from our relationship. We ultimately want what is best for us in the long run and for us right now, that means being apart and growing individually."
Demi continued, "We have felt so much love and support from you all as you've followed our journey together and for that we are grateful. We will forever be proud of the impact our love story has made and we hope it has helped others feel more accepted and confident within themselves."
"We hope it reminded others they aren't alone and don't need to be ashamed of who they are."
Demi concluded, "And we hope it shows that two people can love one another in different ways and for us right now that is apart. But we remain committed to encouraging each other, supporting each other and continuing forward in a way best for us."
In addition to sharing the same statement, Kristian wrote in her Instagram Stories, "You will always have a piece of my heart," on a picture of Demi's marriage proposal on the beach in Mexico. Demi replied, "Same," along with a red-heart emoji.
Prior to their breakup announcement, a source told Us Weekly that Demi had "brushed off" a question about Kristian on October 29.
"There's no way they're together," the source said, although Demi was wearing her engagement ring at the time.
But fans had already been speculating for weeks Demi and Kristian's relationship was over because the girls last shared photos of each other on Instagram on September 19, which was two days after the Season 6 finale of Bachelorin Paradise aired on ABC.
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Demi told Us Weekly on October 9, however, she and Kristian were just really busy and forced to spend time apart due to their hectic schedules.
"Every relationship is different and it's like -- I mean in the most respectful way -- it's nobody's business how our relationship works. We both have so much going on right now," Demi said at the time.
Demi and Kristian currently both live in the Los Angeles-area but apparently never moved in together.
"Just because we don't broadcast [our romance] doesn't mean that we're not together," Demi told Us, shooting down rumors the couple may have split or their relationship was on the rocks.
"We're not too far apart. I think it's important to kind of have our space just so, you know, we can develop a normal, very solid, steady relationship."
Demi, however, told Us that she and Kristian had yet to get the ball rolling on wedding plans.
"If you just jump into it and just rush everything, for me personally, that's not how I could have a successful relationship," explained Demi, who competed for Colton Underwood's heart on The Bachelor's 23rd season prior to her Bachelor in Paradise appearance.
"I have to definitely take it at a steady pace. We're definitely just dating right now. There's so much going on for both of us that it's like, 'Oh, planning a wedding right now just sounds so intense.'"
Demi added that she and her then-fiancee were "definitely taking it slow" and "just enjoying" their time together.
"Just finding time for everything has been really crazy, but other than that, everything has been so fun and it's been so good," Demi noted at the time.
Demi respected Derek and thought he was an amazing man, but she couldn't stop thinking about a girl back home, Kristian, whom she had been dating prior to her appearance on the summer spinoff.
Demi found herself so conflicted between her feelings for Derek and her lingering or unresolved feelings for Kristian that Bachelor in Paradise welcomed Kristian on the show so Demi could figure out where her heart was truly leaning.
Once Demi reunited with Kristian in Paradise, the women were able to further explore their connection. Demi knew immediately upon seeing Kristian in Mexico that they were meant to be, and so Demi let Derek down gently.
Demi and Kristian then continued to date and fall in love while surrounded by their supportive co-stars.
After enjoying a Fantasy Suite date together, Demi proposed marriage to Kristian on the beach and presented her with an engagement ring during Bachelor in Paradise's finale.
The reunion special subsequently featured Kristian proposing marriage to Demi and offering her a diamond sparkler as well.