@j_evans8209 / Instagram 1 / 6
@j_evans8209 / Instagram 1 / 6

"Teen Mom 2" star Jenelle Evans had an inkling that she would leave her recent vacation as an engaged woman, but she wasn't totally sure.

But after her longtime boyfriend Nathan Griffith got down on one knee and slid a rock on her finger in front of a crowded restaurant in St. Thomas, Jenelle was on cloud nine.

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"[Nathan] just tapped his glass, stood up in front of the whole restaurant, and made this big speech," she told MTV. "How he loves me, he wants to be with me for the rest of his life. And he's really happy. And then he got down on one knee and proposed in front of everyone."

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The reality-TV star admitted that she somewhat anticipated the engagement, but was floored by the details of it.

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"I was completely shocked," Evans said of the proposal. "I think I had an idea he would probably propose to me here, but I didn't know when during the week he was gonna do it. And I didn't know what was gonna happen or anything. So it was like expected, but unexpected."

The couple, who welcomed son Kaiser in June, have been together for nearly two years. Janelle also has a son Jace, 5, from a previous relationship.

Much of the couple's engagement weekend can essentially be relived via Jenelle's Instagram page, as she posted multiple photos of their tropical getaway, including her diamond ring.

"He did a perfect job," she said of the sparkler. "We went looking for a month, and then he went looking for four months, because he was so indecisive. He showed all of his friends. He showed everyone the ring, but he would never let me see it."