The 22-year-old crooner paid a visit to The Kyle & Jackie O Show on Sydney, Australia's KIIS 1065 on Tuesday, where he opened up about his new, whirlwind romance with Cyrus and slyly called out her former flames.
"I'm very, very, very romantic," he confessed on the show, adding that, "She'd talked about how she hadn't had that kind of an experience in a relationship before."
Simpson also referred to Cyrus as his "girlfriend," sharing that they are both sober these days and have supported each other in maintaining the clean lifestyle.
"She's been through a lot this year and I was trying to be respectful of that and we kind of found each other," Simpson explained. "We just found each other in a place where we're both ready for something like this and we're both sober… We keep each other in a good space. I've never had that in a relationship."
He also admitted to having a crush on the 26-year-old songstress back when she was an up-and-coming Disney star, stating, "I used to kiss the TV screen when I was, like, nine. I think we were interested in each other ever since we first met, even when I was, like, 18 but it was not the right time."
"We've just been close ever since we met. It's, like, the first time I've been with someone that it wasn't necessarily an immediate romance," he added. "It was a friendship and it was fun and it just developed over, like, five years."
During the chat, Simpson also explained his and Cyrus' logic behind being so forthright with their blossoming relationship with fans, which has included posting loads of fun photos and videos.
"We spoke about it, like, first week, ...we're going to get blown up, right? And we can go about it one of two ways. Getting busted all the time or just, like, not allowing anyone to bust us because we're busting ourselves anyway," he stated.
Simpson also addressed Cyrus' recent comments that "all guys were evil" until she started dating him: "It's a nice thing to say. I'd like to be the best boyfriend I can possibly be. Especially for her. She deserves that much."
However, when asked if he and the fellow singer are using the L word, Simpson demurred: "Love is a big word but, you know, it's romantic."
In early October, the pair was spied kissing while eating out together. Ever since, they've continually shared adorable moments together with fans on social media.
Meanwhile, Cyrus' ex, Liam Hemsworth, appears to have moved on as well. The leading man was recently spotted displaying some serious PDA with actress Maddison Brown in New York City.