The former Bachelor in Paradise couple, who announced their split back in January, apparently got together on May 3 and ordered sushi that got delivered to Kendall's place in Los Angeles, CA, Us Weekly reported.
It appears Joe traveled from his hometown in Chicago, IL, to California to spend time with his ex and they chose to stay in and self-isolate amid the ongoing coronavirus pandemic.
Kendall, 28, and Joe, 33, both posted similar photos of their "delivery sushi" on Instagram Stories, which allowed fans to put the pieces together and determine they were together.
While Joe reportedly deleted his post once fans seemingly caught on to his date with Kendall, more evidence of their reunion surfaced when Venmo users discovered Joe had sent Kendall money for the meal, according to the magazine.
The transaction on Venmo was reportedly labeled "Sushi," and even Dancing with the Stars pro Sasha Farber noticed it and commented.
"Which sushi place?" Sasha commented on the mobile payment service.
Neither Kendall or Joe reportedly replied.
Kendall and Joe -- who met on Season 5 of Bachelor in Paradise in Summer 2018 -- split after more than one year of dating and talking about an engagement, but they said they had an "amicable" breakup and remained friends.
Kendall, for example, wrote to Joe on social media last month, "Happy Birthday Butthead."
But around that same time, Kendall admitted on Instagram she "loved him enough to see a marriage and a future."
Kendall and Joe officially got an apartment together in West Hollywood, CA, in April 2019.
However, in late January they announced they had decided mutually to part ways because they couldn't agree on a city in which to settle down, given neither Joe (who is from Chicago) or Kendall (who is from Los Angeles) wanted to live far from their family long-term.
In March, Kendall said she wanted to "get out there again" and date, but she didn't seem totally ready for a new relationship.
"I feel like if love comes my way, I won't push it away," she said in March. "But I'm also not desperate for it."
"I think ultimately Joe saw his happiness and work in Chicago, and I can't resent him because of that," Kendall shared with ET in March.
"And for me, I just never foresaw a future there, so, I think it became an ultimatum within itself where either I move to Chicago or we broke up. And I didn't really want to have a relationship like that."
Kendall also said she and Joe were broken up for "about a month" before they dropped the news and went public with their relationship status.
"And we were living together during that time too, which is a little awkward. But I feel like it helped us get everything out of the way so we had no questions and we just agreed mutually that it was best that we separated," Kendall explained, adding that Joe taught her what she does and does not want in her future husband.
Fans were shocked when Kendall and Joe's breakup was announced because the pair had just teased they could be getting engaged soon in December 2019.
Kendall and Joe's relationship initially got off to a rocky start when Kendall blindsided and dumped Joe during the penultimate episode of Bachelor in Paradise's fifth season after he professed how he was falling in love with her.
Kendall found herself making a stream of excuses on the beach in Mexico as to why their relationship wouldn't work, but Joe called her out for simply being unaware of her feelings for him or not reciprocating them at all.
Joe therefore left Paradise confused and heartbroken, while Kendall clearly felt there was more she could have said and the pair had unfinished business.
"I felt an immediate regret as soon as Joe walked away... I kept running away from the fact that I was falling for him," Kendall admitted to People in September 2018.
"I went into Paradise thinking you need to date, you need to be open-minded, you need to experience people... I also had so much fear about getting hurt... It freaked me out to think I would invest myself in him and then it would break apart after the romantic beach vacation was over."
However, Kendall flew straight to Chicago after the show wrapped to talk to Joe again in-person and apologize, and she expressed to him on-camera, "I am in love with you."
It took some time for Joe to trust Kendall again, but the couple ultimately reconciled and rekindled their romance in the real world. Joe, without a doubt, was in love with Kendall as well.
Joe subsequently competed on Season 27 of Dancing with the Stars in Fall 2018 in Los Angeles, and he was able to remain close to Kendall at the time given she lives there.
Their relationship blossomed from there until Joe apparently realized he didn't want to stay in California.