James Middleton and girlfriend Donna Air are one of the most private couples around, but the English actress posted a rare photo on her Instagram snuggling with Kate Middleton's brother.

About two weeks ago, the TV presenter shared on her Instagram a selfie of her beaming as she leaned against James Middleton's chest. Kate Middleton's brother had a full-on beard and had his arm around his girlfriend.

Donna Air captioned the image, "Hiking in the hills. #morning #sunrise #LA #breakfast."

One follower commented, "Gorgeous couple."

A friend said, "Gorgeous couple! FYI weathers been great back here - lets do drinkies in the garden when you're back!!"

Another noted, "Looks like a giants hand around you!! #cutecouple."

But one of her followers couldn't help but observe, "That beard is out of control!"

Except for the early morning hike in Los Angeles, most of the photos shared by Donna Air on her Instagram didn't have boyfriend James Middleton.

Donna Air, in an earlier interview, said that James Middleton "is wonderful, and I enjoy our time together very much."

"I am very happy. It is early days but you just never know what the future has in store," she said of Kate Middleton's brother. "And yes...there is also the bonus that he brings something I have always searched for, and will always need in my life... cake!"

James Middleton and girlfriend Donna Air started seeing each other early 2013 when they met in Mayfair in a private members' club of Robin Birley. They went public with their relationship in April of the same year.

Before dating Kate Middleton's brother, Donna Air was with casino owner Damian Aspinall, with whom she has a daughter, Freya.

"The sweet couple are understandably discreet when it comes to their romance, but they occasionally let their guard leaving onlookers in no doubt just how besotted they are," Hello! Magazine said.