Miley Cyrus and Patrick Schwarzenegger

Miley Cyrus and Patrick Schwarzenegger

Miley Cyrus and Patrick Schwarzenegger were "really affectionate" while Christmas shopping in Beverly Hills, California.

The couple reportedly "appeared happy and seemed in great moods" as they bought gifts at a number of shops on Rodeo Drive on Tuesday (16.12.14).

An eyewitness said they walked hand-in-hand, and also told E! News: "They are really affectionate with one another. They look like a really happy couple."

Meanwhile, the 'Wrecking Ball' hitmaker is planning to surprise her new beau with a unique gift.

A source told Us Weekly she has been writing and recording a new song dedicated to the 21-year-old student, who is the son of Arnold Schwarzenegger and Maria Shriver.

The duo's romance is said to be getting serious, but they declined to pose for photos together after showing up to Brooks Brother's shopping event benefiting St. Jude Children's Research Hospital on Saturday (13.12.14).

A source recently said: "They were holding hands and didn't want to take photos together. They were very nice and took photos with the DJ who is Oscar Adler."

Miley - who ended her engagement to Liam Hemsworth in September 2013 - and Patrick were introduced by mutual friends, but "couldn't be more different" to each other.

A friend previously said: "They started out as friends and then segued into more."