The 23-year-old singer rocked a 1960s-inspired canary yellow mini-dress with knee-high white boots and a smiley face handbag, while Hemsworth, 26, dressed down in a ballcap, a colorful, street-art-styled jacket and black skinny jeans.
Sitting down on The Ellen DeGeneres Show last month, the "Wrecking Ball" singer addressed the ring, sharing, "It's very weird because this is, like, real jewelry and most of my jewelry is made out of like gummy bears and cotton candy and they don't look that good together because they kind of mix up."
"So sometimes I replace it with an actual unicorn or a Looney Tune," she continued. "And he's like, 'What's going on?' And I'm like, 'Well, this isn't my aesthetic, but I'll wear it 'cause you love me.'" Check out the video below to hear more.