Although The Bachelor doesn't premiere until January 6, a promo was released last month on ABC of Hannah making a surprise visit to see Peter -- who finished in third place on her The Bachelorette edition -- while he was filming Season 24.
The promo that aired on Dancing with the Stars' Season 28 finale showed Peter asking Hannah to join his season's cast.
Hannah, however, encouraged Bachelor Nation to take into account she had been competing on Dancing with the Stars while The Bachelor was filming from September to November.
"I feel like if we put two and two together, like, I worked my ass off to win that mirrorball. So, I don't know [how much you're going to see me on The Bachelor]. I was in the studio eight hours a day," Hannah, 25, toldEntertainment Tonight on Friday when asked what fans can expect from her The Bachelor appearance.
"You can do the math and watch in January."
Other than filming a couple of scenes with Peter during his time in Los Angeles, Hannah's commitment to Dancing with the Stars would have prevented her from traveling for The Bachelor and committing to being one of Peter's contestants.
But the trailer showed Peter and Hannah still have chemistry, without a doubt.
When ET asked Hannah why she visited Peter on his season and whether there were "some unresolved feelings" between the former couple, Hannah giggled nervously and dodged the question.
"You'll have to wait and watch in January," Hannah repeated, referring to the show's three-hour premiere event. "That's actually all I'm going to give ya."
In the promo, Hannah and Peter were filmed sitting side-by-side on a sofa.
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"I'm so confused right now. What are you doing here?" Peter, 28, asks Hannah in the clip, which aired on Dancing with the Stars after Hannah took the stage with her professional partner Alan Bersten.
"I'm making decisions for my heart, because I know there's still something there," Hannah replies. "And I would do anything for a relationship."
Hannah and Peter's flirtatious body language teased a potential reconciliation given Peter leaned in close to Hannah and nearly tried to kiss her.
Peter then proceeded to invite Hannah to become one of his bachelorettes and compete for his heart.
"Hannah Brown, what I'm about to say is extremely crazy. What would you say if I asked you to come and be part of the house?" Peter asks Hannah as he rubs her back and she giggles.
Women were shown eavesdropping in on the conversation from a distance and yelling, "Oh my God!"
And in a second promo for the new The Bachelor season that aired later during the Dancing with the Stars broadcast -- which concluded with Hannah being crowned champion over three other finalists -- Hannah stepped out of a limo at the show's Malibu mansion.
According to Reality Steve spoiler blogger Steve Carbone, The Bachelor viewers shouldn't read into the promo of Hannah and Peter's reunion too much.
"B4 everyone freaks out when first promo airs tonight," Carbone tweeted late last month before the DWTS finale began airing, "Hannah WAS NOT a contestant on Peters season."
"She gets out of the limo to talk to him night 1 (didn't join the party), & shows up on a date in ep 3 again to talk," he continued. "Both were in LA. She just took a couple hrs off DWTS to do it."
Hannah admitted to People in July she was "in love with Peter" but her heart was pulling her in different directions on The Bachelorette's fifteenth season. She ended up getting engaged to aspiring country singer Jed Wyatt, but she broke up with him five weeks later.
"But I had to make a decision," Hannah said at the time of Peter's ouster. "I felt like my heart was broken... What I'll miss most about Peter is his genuine love for me. The time we had together was real."
Hannah currently seems to be single and anticipating new opportunities in 2020.
"I think there's going to be a lot of things in store for me and I think you have to manifest that," Hannah told ET.
"But I have realized I thought I wanted a break -- I had a break, for like a week, and I hate it. I think I love crazy. I love a crazy life. I want to be booked and busy. But I don't want to give too much right now... You'll see more of me hopefully."
Hannah revealed she'll be dancing in New York during one of the stops of Dancing with the Stars' upcoming tour.
And as far as her "grand dreams" go, Hannah would apparently love to write a book one day or have her own talk show on TV.
To learn more about Peter's The Bachelor bachelorettes, click here. To discover which three bachelorettes finished as Peter's Final 3, click here, and for some juicy information on the ending of Peter's season, click here.