Could wedding bells be ringing soon for Prince Harry and his girlfriend of 18 months, Cressida Bonas?

The 29-year-old royal met Bonas's father, Jeffrey, for the first time before taking off to the South Pole for a Wounded Warriors 200-mile walk for charity. Prince Harry reportedly asked for Cressida's hand in marriage before he left.

"It seems that Harry and Cressida have spoken about marriage, he wanted to do the honorable thing and meet her father to let Jeffrey know his intentions before he went to the South Pole," a source said. "It's always scary meeting your girlfriend's father, but Harry knows how close Cressida is to her family. He wants to ensure they're on-board for when they announce an engagement."

The 24-year-old's father agreed to let Prince Harry and Cressida tie the knot when they are ready.

Prince Harry Girlfriend Cressida Bonas Invited to Queen's Private Home, Details

"They get on really well and enjoyed a few games of golf. Harry had 'the chat' with Jeffrey and tentatively asked for his daughter's hand in marriage," the insider added. "Jeffrey gave his blessing for when the time is right."

Cressida was spotted Wednesday arriving at a carol service to honor a close friend of Prince Harry and Prince William, Henry van Straubenzee, who died at 18 in a car accident before Christmas in 2002.

Dressed casually in jeans and a sheepskin coat, with her hair pulled up in a ponytail, she also held on to a book called Why Love Matters. While this might seem like she's sending a message to Prince Harry, it is actually a book that focuses on child psychology and how a baby's brain develops and grows. She was also carrying another book titled Prospective on Play, a book for those who aspire to teach nursery and primary school students.

Prince Harry's ex-girlfriend, Chelsey Davy, as well as Duchess Kate Middleton's mother, Carole, also made an appearance. 

Prince Harry's Girlfriend Cressida Bonas' Brother Slams Rumors That The Two Will Getting Engaged '[It's] Ludicrous' [VIDEO]

Cressida is rumored to be thinking about becoming a teacher after giving up her dream career as a dancer, Enstars previously reported. She believes this will help her maintain a career of her own while dating the royal.