Behati Prinsloo talks to Us about her surprise engagement to Adam Levine, their wedding plans -- plus, get the details on her ring! Credit: WireImage

Behati Prinsloo is on cloud 9! On Thursday July 18, the Namibia-born model, 24, made her first official appearance since she and Adam Levine confirmed their surprise engagement; promoting the new Victoria's Secret fragrance in NYC, Prinsloo chatted with Us Weekly about her happy news.

The blonde stunner admitted that the reality of it all hasn't hit her yet "at all. I forgot I slept with [the ring] on last night, and I woke up and went, 'Oh, hello!'" The catwalker didn't have a hand in picking out the engagement ring -- "it was a surprise!" she said.

The bauble itself is vintage, featuring an oval diamond in a raised setting on a thin, dark silver band. 

Wedding plans, so far, are TBD, Pinsloo admitted. "I'm so laid back -- my mind has been going but we haven't talked about anything! We're just so excited in this moment! I'm like, 'Yikes!'" (Prinsloo and the Maroon 5 rocker, 34, celebrated at Peels eatery in NYC Tuesday with champagne and burger.)

When the couple of about one year (who reconciled earlier this month following a springtime split) do walk down the aisle, she says, "I want all of our friends and family there, so however big that is going to be . .  It hasn't even sunk in yet!" 

Prinsloo previously told ET Canada that her Voice coach beau proposed on "one-knee It was serious, it was very old school."