It looks like Prince Harry and girlfriend Cressida Bonas are getting pretty serious. Prince William of Wales' little brother's royal invite asking the blonde beauty to join him for a hunting trip at the queen's 20,000 acre Sandringham estate on October 26th was more important than we thought.

According to Us Weekly, a source said that such a gesture extended to the Norfolk countryside is a big step for the relationship, not to mention that the estate is also the site of the royal family's Christmas celebrations.

The insider revealed, "She's now part of Harry's inner sanctum," adding, "The fact that she's been to Sandringham on numerous occasions proves that she's been welcomed into fold. She's a lovely girl and everyone is hoping they go the distance."

We all know that Prince Harry's 24-year-old girlfriend has not been the first woman to be invited to the estate for a weekend. Some may recall that Kate Middleton visited the Queen's home a number of time times before Prince William finally proposed to her in November 2010.

Harry, 29, and Bonas were first romantically linked to one another in June 2012, when they attended a London party together with friends.

A source admitted, "He loves her -- they're so compatible," adding, "Cressie is very laid-back and he likes that. If all goes well, I'm 100 percent sure they'll be engaged next year."

Do you expect to hear a royal engagement announcement anytime soon? Let us know your thoughts in the comment section below.