The 36-year-old proposed to Lauren Burnham soon after breaking things off with fiancée Becca Kufrin, on Tuesday's After the Final Rose special.
"I've made some bad decisions, but the best decision was running back to you," Arie told Lauren before dropping to one knee. "I truly believe you are my soulmate."
"Definitely," she replied, to muted applause from the crowd.
"I feel betrayed," Lauren said while crying in the loser's limo. "How could you do that to somebody?"
But just weeks after promising to "choose [Becca] every day" in their marriage, Arie told his fiancée he couldn't stop thinking of Lauren.
"I go to bed and I think about Lauren, I wake up and I think about Lauren," he told the blindsided woman.
Leaving her confused and heartbroken, Arie traveled to Lauren's parent's home in Virginia to see if she would take him back, a task he said was giving him a "panic attack."
But after admitting she was initially "angry" with him, Lauren welcomed Arie with open arms...literally.
"I felt like I was making a safe decision for my future...and I think I let the logic side of myself take over the emotional side of myself," Arie explained to Lauren, adding that a conversation the two had on a phone "changed everything for me."
"Do you think you're 100 percent over Becca?" Lauren asked, to which Arie replied, "Yes, 1,000 percent."
After telling Arie she forgave him, Lauren agreed to take him back, leading to one of the most maligned Bachelor Nation proposals of all time. We can't wait to see how this all turns out.
"I've never been more in love with him," Lauren told host Chris Harrison during the special, praising her beau for his "bravery" and "honesty."
"I think in a crazy way, this has made our love stronger," Arie added. "No love story is perfect. And I think for us, I took that risk because it was worth it."
Photo credit: ABC