The Twilight star tells People Magazine she is still taking in being a fiancee.

"I look down at my hand every once in a while and I'm like, 'Oh yeah, I'm engaged,' which is crazy, but as always, we're keeping it easy and fun and not stressing about anything that's to come afterwards - we're just enjoying this moment," she says.

Greene also remains in awe of her engagement ring, which her husband-to-be helped design.

"I would expect nothing less of him," she gushes. "He's extremely creative and so it's not surprising that he spent that much time (on the ring). He wanted it to be really special for me and one of a kind and (for him) to have a part in creating that makes it that much more special."

The 29-year-old, who began dating the Australian TV host in 2013, insists the key to their happy relationship has been communication.

"The great thing about him and I is that we have a great open line of communication about where we are, what we want and where we want to go in the future," Greene shares. "So I feel like we're kind of going along this path that feels right for us."

But the actress isn't consumed with planning their big day just yet.

"I'm sure my mother is already planning," she smiles. "But we're not going to be doing anything soon."

Greene first shared news of her engagement in December (16) via Instagram, by posting a video of Khoury proposing.

"I'm SO lucky and SO excited that I get to spend the rest of my life with my best friend but the ring doesn't hurt either," she wrote in an accompanying post. "It's the most beautiful thing I've ever seen."

Khoury popped the question while they were vacationing in New Zealand.