"Yes...I am engaged," the 23-year-old “90210” star tweeted on Friday. "Thanks for all the congratulations everyone, I'm a very happy lady indeed and all the warm wishes are well appreciated! We plan to keep our special day very private and we hope everyone can respect that. Thanks for the love, right back atcha!"
The two began dating nine months ago.
Grimes next stars in “Empire State,” opposite Liam Hemsworth.