Prince Harry and Meghan Markle celebrated his 33rd birthday last week. Pictured: Harry takes part in a training session during a celebration for the expansion of Coach Core at Lord's Cricket Ground on Oct. 7, 2016 in London. Getty Images/Ben A. Pruchnie

Prince Harry will be turning 33 on Friday, Sept. 15, but the Duke seemed to have been eager to start with the festivities as he chose to celebrate his special day last week.

Prince Harry reportedly had a low-key birthday celebration over the weekend with his girlfriend, Meghan Markle. The "Suits" star flew to London, so they could celebrate the royal's birthday together, E! News reported. A source told the publication that the couple "quietly celebrated his birthday together on Saturday as she wouldn't be with him on the day of."

One reason why Prince Harry apparently decided to go for a simple celebration is that he does not like making a big deal out of his birthday. "Harry doesn't like to make a fuss of birthdays so he liked that it was just the two of them. Sometimes it doesn't have to be a huge thing with a group of friends," the insider added.

The source added that Markle will not be able to fly to London on Prince Harry's birthday as she has a prior commitment. She has to be in Toronto to film the second half of "Suits" Season 7.

Meanwhile, rumors previously surfaced that Prince Harry proposed to Markle during their three-week vacation in Africa. However, neither of the two has confirmed the reports. But though they have not acknowledged the engagement rumors, there is no denying that their relationship is going strong.

Another insider claimed that being apart from each other is difficult for the couple. This is the longest time that they will be away from each other, but Prince Harry is expected to fly to Toronto soon. He will be in Canada from Sept. 22 to 30 for the Invictus Games. It is expected that Markle and Prince Harry will make their first official appearance as a couple during the event.

"He won't be staying at Meghan's house during this trip due to security but they will be together for all of his down time," the insider told E! News. "Harry will spend a day with Meghan before beginning Invictus-related engagements on Sept. 22. Naturally, Meghan will be present for some of the games and you'll no doubt see them together in the stands, but she won't be taking part in any of the engagements in an official capacity."

Meanwhile, the "Horrible Bosses" star recently confessed in an interview that they are in love. Markle has kept mum about her romance with Prince Harry over the past several months, so many were surprised when she finally opened up about their relationship. She also said that in time, they will come forward to present themselves, but at the moment they are enjoying their relationship and are happy together.

Do you think Prince Harry and Markle will announce their engagement soon? Drop a comment below.