Reports say Prince Harry and his girlfriend Cressida Bonas are secretly already engaged, but are waiting for the right time to make it official to the public.

A source told British magazine Grazia that Prince Harry, 28, and Cressida Bonas, 24, may already be engaged but are waiting to go public with the news, Fashion & Style reports.

"It's only a matter of time before Harry makes it official. They've discussed it at length together and with their families," a source said.

"Some of their friends reckon they might already be engaged, but are waiting for a while to go public."

The Independent reports that Harry might have been inspired to keep his marriage news a secret by his older brother Prince William, 31. Prince William gave his now-wife Kate Middleton a few months to decide if she was ready to accept his marriage proposal before they officially announced it in 2010. The pair later revealed they had been planning the move "for at least a year," The Independent notes.

Cressida is believed to be nervous about getting engaged, marrying a prince with a royal wedding, and accepting a high-profile life, The Independent reports.

However, she is apparently spending most of her time at Harry's apartment in London and taking some time to adjust to the idea of taking on a public role.

"Harry has done everything to assure Cressida that she could cope. Living at Kensington Palace with Harry has helped," the insider added. "Harry loves Cressida and wants to settle down with her, so he's been preparing her for royal life in private. She's met his family and [his father] Prince Charles knows of their plans.

"Cressida loves what she does and Harry has assured her she can continue with her career. He has told her that if his sister-in-law, the Duchess of Cambridge, can be happy as a royal, so could she."