The 67-year-old reality star recently made headlines thanks to his appearance on The Dr. Oz Show, which aired on Monday, in which he tearfully proposed to Angell. The shocking proposal comes almost seven months after his beloved wife, Beth, died last June after her battle with throat cancer.
Chapman prefaced the proposal by saying Beth wanted him to be happy.
"Well, one time she said, if something would happen, because I always said, 'You're not going to die. Don’t worry, you’re not going to die,'" he said to Dr. Oz as Angell sat next to him. "I held that to the very last breath, 'You're not dying.' And she said, 'I want you to be happy.' And I didn't tell you I was going to do this, but this is The Dr. Oz Show. I think this will put a stop to a lot of this. Moon Angell, will you marry me?"
Angell was visibly shocked, and responded, "What?"
However, Angell did not accept the proposal, telling Chapman they were just friends.
"We're friends Duane," Angell said. "I love you as a friend."
"I can't marry you," she continued. "Right at this very moment, I don't see you as that. I love you and Beth as my friends."
Chapman said he already knew that, and agreed with Dr. Oz that the proposal was just a test. He said he already knew Angell didn't see him romantically, but that he just wanted "everyone else to know, too."
During the episode, the two also addressed a past tweet by Chapman's daughter, Lyssa, which criticized Angell for moving her clothes into Beth's closet.
"If someone who met your family by dating your brother, tried to date your father after your step- mom died what would you do?" Lyssa wrote. "If you went to your mothers closet and saw she moved all her clothes and replaced them with her own, what would you do? #ItsNotWhenOrWhyItsWho. My dad is a GROWN A** MAN. His money. His dynasty. But you can guarantee that my name is not going down in history as a person who supported this."
Angell explained that Chapman actually asked her to take Beth's clothes out of the closet because he was too overwhelmed with grief whenever he would pass by and see it.
"So, it wasn't a negative thing, it was just because he couldn't do it anymore," she said.
Chapman then tearfully noted that he asked Angell to put some of her things in there because he also couldn't bear seeing that it was empty, and that he ordered her to do it even though she protested.
Last month, a family source told ET that despite romance rumors between Chapman and Angell, the two were just friends. Angell and Chapman have known each other for 30 years, and she's served as the reality star's long-time assistant. The source said that Angell helped Chapman with everything from cleaning up around the house to cooking.
"This [Angell] is not somebody who showed up yesterday," the source noted at the time.
ET spoke with Chapman in September, and he talked about when he might date again. Chapman said that he and Beth had, in fact, discussed him moving on romantically after her death, and she told him to never get married again.
"There will never be another Mrs. Dog," he told ET, adding that he's not sure how long it'll be before he pursues a serious relationship.
He did admit feeling intensely lonely.
"It's really hard alone, because as soon as you get alone, bam, it hits you. So, I try not to be alone," he shared, noting that his bounty-hunting team and children have been looking out for him. "Sometimes they know I gotta be alone, but it hurts worse or you feel it more when you're all alone."