Jared Haibon popped the question to Ashley Iaconetti while in Mexico for the upcoming fifth season of Bachelor in Paradise

Only happy tears here!

Ashley Iaconetti and Jared Haibon are engaged, PEOPLE confirms. Haibon popped the question Sunday while in Mexico for the upcoming fifth season of Bachelor in Paradise, the summer spin-off series where The Bachelor alums’ up-and-down relationship began three years ago.

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Haibon got down on one knee on the beach as the bride-to-be, wearing a bright yellow dress, put her hands on her chest and threw her head back in excitement.

“Ashley and Jared are both so excited about the engagement,” a source tells PEOPLE. “Ashley had her suspicions that an engagement would happen in Mexico but she didn’t want to get herself too psyched out and then have nothing happen. They’re both thrilled though!”

Image zoom Ashley Iaconetti and Jared Haibon ABC/Paul Hebert

Fans remember Iaconetti, 30, being crushed on the second season of Paradise in 2015 when Haibon, 29, didn’t reciprocate her instant feelings of attraction. However, the two remained close and built a strong friendship.

During a weekend spent in Virginia with their friends for a charity event Iaconetti was planning, Haibon saw her in a different light. “I was in love,” he previously told PEOPLE. “That was such a different experience being with someone in the show and in real life. [Iaconetti was] just so down to earth and easy-going, ambitious … sexy.”

Added Iaconetti, “I knew that he was looking at me!”

Though they frequently hung out throughout the fall and were “flirty” with each other, the timing was never right, the pair said.

After her Bachelor Winter Games romance with Kevin Wendt fizzled out in March, Haibon poured his heart into an emotional love letter that took three days to write. “I was scream-crying basically alone in my apartment reading that just sobbing and sobbing,” said Iaconetti.

They officially confirmed their relationship in late May, and recapped their journey for fans in a tear-filled episode of Iaconetti’s show The Story of Us.

Image zoom Ashley Iaconetti and Jared Haibon Tommaso Boddi/Getty

“There’s just this undeniable, magnetic force between the two of us that just is indescribable,” Haibon told PEOPLE at the annual Nylon Young Hollywood Party last month. “Love conquered.”

When asked if they have talked about marriage, the couple was open about the fact that they had considered their future, but were happily enjoying their dating life.

“As soon as we started dating, we both knew that this isn’t just for us to date as boyfriend/girlfriend — this was more so we were going to date because we see a potential life partner in each other,” Haibon explained. “We’ve talked about it but we’re just dating right now, we’re enjoying that. We literally just announced our relationship. The thing is, we’ve been so close for the past three years, I just know her inside and out. I know everything about Ashley.”

RELATED VIDEO: The Story of Us – Ashley and Jared

In fact, the duo are already comfortable calling each other “husband” and “wife.”

“I said, ‘Then you met your wife,’ which is kind of crazy, but it’s just because we talk about the future all the time,” Iaconetti said at the iHeartRadio KIIS FM Wango Tango by AT&T earlier this month.

“I think we just both see each other as lifelong partners, so it’s not scary, for me personally, to call her my future wife,” Haibon explained.