"Not gonna lie -- it's been nice keeping this to myself, but it's about time y'all know too," Tia, 30, captioned the video.
The video shows that Tia and Taylor have attended at least one wedding together. They clearly have a playful dynamic having struck underwear poses, and clips captured the pair enjoying doggy snuggles and cooking meals together.
Many The Bachelor and The Bachelorette alums weighed in on Tia's romance, including Becca Kufrin, who commented on behalf of boyfriend Thomas Jacobs and wrote, "We approve. Get those double dates lined up soon."
While Tia, originally from Arkansas, didn't specify how long she's been dating the California native, Taylor confirmed the pair -- who currently live in Nashville -- are definitely in love.
Taylor captioned a slideshow of photos with Tia this past weekend, "It's hard to put into words how you truly feel about someone you love."
"I guess I'll keep it as simple as I've never felt more alive than when I'm with you," Taylor continued. "With that being said I still had to make fun of you, hope everyone enjoys the last two slides."
Taylor also included two funny videos of Tia asking "Why?" in her southern accent and smiling but in a tight hoodie sweatshirt over her head.
Tia originally competed for Arie Luyendyk Jr.'s heart on The Bachelor's 22nd season and made it to hometown dates before he sent her packing. She also appeared on Bachelor in Paradise twice, with her latest stint having taken place this past summer.
Tia seemed most interested in Blake, but he didn't put enough effort into their relationship, according to the bachelorette.
Tia revealed on Bachelor in Paradise that she has a history of dating men "who don't care" enough to woo her, and she's a person who believes in actions speak louder than words.
When Bachelor in Paradise was still airing, Tia shared on Instagram Stories, "I saw Thomas go by with a tray of chicken nuggets for Becca and a bunch of pics of their dogs just to be cute and sweet for her."
"And this dude," Tia continued of Blake, "says, 'You know I'm not gonna set up anything for you right? You should know how I feel about you. All that stuff other guys do is fake for TV.'"
Tia posted three embarrassed emojis after making her claim and added, "And I lost my mind."
Tia pointed out, "This ain't my first rodeo. It ain't that hard. Gimme nuggets & fries."