The reality stars declared their love for each other during a weekend road trip

The couple, who met during 2014’s Survivor: Worlds Apart, began dating last year and soon fell in love. But Thomas had no idea that Anglim had a surprise engagement in store for her.

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After attending Anglim’s sister’s wedding in Arizona over the weekend, the pair was driving back to Utah when they stopped to camp for the night.

“We pulled in just as the sun was setting, and we decided to go for a little walk,” Thomas, 32, tells PEOPLE. “We found the perfect swinging chair facing the mountains and the most beautiful sunset. There were even some deer running across a dirt road!”

“We popped a bottle of rosé,” she continues, “and we were cheering in our clear plastic cups!”

Image zoom Sierra Dawn Thomas/Instagram

Image zoom Sierra Dawn Thomas/Instagram

Thomas didn’t even suspect anything when Anglim started declaring his love to her. “I was unknowingly interrupting him,” she laughs. “He was explaining his love for me, and I would say, ‘yeah, baby. I love you too!’ ”

“But then he got off the swing, reached into his coat, and got on one knee,” she says. “It finally hit me what he was doing. I started crying, and he started crying! We were both crying.”

Anglim, 30, gave Thomas a teardrop-shaped ring. He slid it on her finger and kissed her hand. (Spoiler alert: She said yes.)

Image zoom Sierra Dawn Thomas/Instagram

Anglim is appearing on the current season of Survivor: Edge of Extinction. He previously competed on Worlds Apart and Second Chances, and was voted off after being perceived as a physical threat.

Thomas finished Worlds Apart in 5th place, before returning to Survivor: Game Changers, where she was voted out on day 32.

(Fun fact: on their first season together, Thomas actually voted Anglim off. He’s clearly gotten over it.)

Although the couple hasn’t yet set a wedding date, they’re both ecstatic about their engagement.

“I had no idea it was coming,” Thomas says, “but we’re going to live happily ever after!”