Hannah eliminated Peter in third place on The Bachelorette's fifteenth season in favor of runner-up Tyler Cameron and winner Jed Wyatt in 2019, but after her engagement to Jed failed, she admittedly still had feelings for Peter while he filmed The Bachelor's 24th season.
Once Peter broke off his engagement to The Bachelor 24 winner Hannah Ann Sluss in late January 2020, Hannah wrote in her upcoming book, God Bless This Mess: Learning to Live and Love Through Life's Best (and Worst) Moments, that she and Peter reconnected at Bachelor in Paradise couple Dylan Barbour and Hannah Godwin's February 2020 engagement party, Us Weekly reported.
Hannah reveals in her book that she and Peter left the party together to catch up somewhere private and they ended up at the home of Peter's parents in Los Angeles, CA.
While Hannah began sleeping in his little brother's room, Peter allegedly texted Hannah to join him in his own bedroom, and Hannah obliged -- which resulted in the pair having sex.
Unfortunately, the sexual encounter was apparently a disappointment for the 27-year-old former Alabama beauty queen.
"I think it's relatable. I mean, maybe not the parents' house, but [people can] definitely [relate to] making a poor decision when you're hurting. And I think a lot of girls can relate to that," Hannah told Us in an interview while doing press for her book that hits shelves on Tuesday, November 23.
The morning after her tryst with Peter, Hannah claims she had an awkward breakfast with Peter's parents, Barbara Weber and Peter Weber Sr., knowing that her connection with their beloved son had completely fizzled out.
The pilot then called Hannah an Uber and left for work.
The next time Peter and Hannah talked on the phone, Hannah says Peter confessed that he still had feelings for his The Bachelor runner-up, Madison Prewett, who decided to give Peter another chance on The Bachelor: After the Final Rose in March 2020. (But Madison and Peter announced their official split only two days after the ABC special aired).
Although Hannah acknowledged to Us that she was a little "hesitant" to share such intimate details of her past and even "worried" about how people will react, she thought it was important to include stories that have a purpose and can help women going through similar situations.
"Telling that story, I think it just really gives an honest and vulnerable account of what was kind of going on in my life," Hannah explained of her February 2020 hookup.
"There's this buildup that kind of happens, you know, and then my brother has the overdose and the stuff with the quarantine crew."
For weeks beginning in March 2020, Hannah quarantined with Tyler in his hometown of Jupiter, FL, with Tyler's best friends, including The Bachelor Season 25 star Matt James, amid the coronavirus pandemic.
Hannah and Tyler both confirmed in October 2020 that they never hooked up -- or even kissed for that matter -- but the "friendly" reunion created emotional inner turmoil for Hannah, who still had feelings for her The Bachelorette runner-up, and caused the former couple to bicker.
Hannah eventually returned home to Alabama on April 1 single and a bit confused about her love life.
Going back to her rendezvous with Peter, Hannah concluded, "It was, like, this perfect storm that unfortunately there were some mistakes and all that, but [it] led me to getting the help that I needed. So I think that story really was important."
Hannah, however, apparently didn't think it was important to ask Peter for his blessing to write about their sexual encounter. She said she didn't even give him a warning or a heads-up about the explicit material in her book.
"He has not been in the process of writing this book," Hannah confirmed. "And yeah, that's all I'm going to say."
According to People, Hannah writes in her book that her hookup with Peter in February 2020 "just sucked" and "the chemistry just wasn't there." She called the whole ordeal "so bizarre."
It appears Hannah and Peter found their way to each other at the engagement party because they didn't have closure from their time together on reality television.
During Peter's The Bachelor season, Hannah showed up twice.
On Night 1, Hannah returned a flyer's wings clip Peter had given her, and then she hosted a "sex stories" group date, which got derailed when Peter found her alone in a room crying.
Hannah admitted to Peter she had unresolved and lingering romantic feelings for him in a very touch-feely and teary-eyed conversation, and Peter seemed to feel the same way.
"Going back and seeing him as the Bachelor, it brought up a lot," Hannah says in her book, according to People.
"[Off-camera], Peter told me he'd quit the show, 100 percent, if I could say that I wanted to be with him. I wanted to go on a date with him, but I couldn't say that I knew for sure."
As for what was actually shown on television, Peter essentially asked Hannah to join his cast of bachelorettes because they clearly still had intense chemistry, but Hannah seemingly wanted to take off together and try dating in the real world.
Peter actually admitted back in April that he was ready to walk away from his The Bachelor season during filming when Hannah reappeared in his life.
"I was an idiot, producers probably hated me, but I literally, like, I think they edited this part out, I was like, 'I'm gonna leave the show, like, if you want to, if you want to give this a shot, I'll leave right now,'" Peter revealed on Us' "Here for the Right Reasons" podcast.
"And she's like, 'You can't do that, Peter, you're the Bachelor, you signed a contract.' I'm like, 'No, like, I'll do it. What are they gonna do to me?'... I don't know what I was thinking that day. I was very confused."
But the episode showed Peter, recognizing he had been Hannah's third choice on The Bachelorette, deciding to part ways with Hannah once and for all in order to give his cast of women a fair chance.
"Our lives kind of separated there," Peter noted on the podcast.
Once Peter had Hannah, Madison and Sluss in his rearview mirror, he reunited with his fifth-place The Bachelor finisher Kelley Flanagan and the pair quarantined together in Chicago beginning in March 2020.
What supposedly started out as a friendship quickly turned into a romantic direction and then the couple dated -- on and off -- until they announced their split in February 2021.
Peter said in April that he's "super happy" for Hannah and her current relationship with boyfriend and model Adam Woolard.
"I see she's in an awesome relationship... and so that just makes me super happy," Peter shared. "And she's an amazing person. And I've got nothing but great things to say about her."
For Peter's part, he reportedly recently joined a dating app and is interested in dating a woman outside of Bachelor Nation.