In "Laguna Beach," romances were an integral part of the MTV teens' lives -- yet Season 2 cast member/new girl Casey Reinhardt managed to steer clear of all the love triangles and keep her connections with the fellas out of the spotlight. But now, the SoCal transplant has some big news to share with the public: She's engaged!

"My breath is taken away... I've never felt happier in my entire life!!!" the "Casey’s Cupcakes" founder captioned the sweet Instagram image above with her fiancé Sean Brown, taken mid-proposal. "I love you so much @seanmbrown1!!!! How lucky am I to have found my soulmate... I can't wait to spend the rest of my life with you!!!!!!!!!!! Happiest day of my life!! I feel so blessed!!!"

Doug Reinhardt's sister -- you know, he dated Lauren Conrad and Stephanie Pratt on "The Hills" -- followed up her initial announcement with a snap of her soon-to-be husband and her ginormous pear-shaped ring below. Holy bling for the sweets queen!

Offer your congrats to the future Mr. and Mrs. in the comments -- and for a fun throwback below, check out the then-LBHS student showing off her room and her car!