Princess Kate Wears Her Royal Christmas Cheer While 'George Is Already Ripping Open His Presents'

Tis the season for royal cheer! Prince William, Princess Kate and Prince Harry celebrated one of their favorite causes on Monday with a festive charity party.

The trio dropped by a gathering of volunteers from their Heads Together initiative, the mental health campaign they kicked off in the spring. Kate brought stylish Christmas spirit with a red-and-green Vanessa Seward dress (currently on sale for $623) cinched with a black belt and $185 fern hoop earrings from London designer Catherine Zoraida.

Meanwhile, William told a deejay at the party that 3-year-old Prince George and 19-month-old Princess Charlotte are a little excited for the holidays.

“He said the kids are really looking forward to Christmas and George is already ripping open his presents,” London radio host A. J. King, an ambassador for the Mix, tells PEOPLE.

William happily said this was the last week of work for the royals.

“They’re looking forward to downtime and a chill with the family.”

The party was hosted by youth support service The Mix to celebrate the volunteers and counselors who support people through tough times in their lives. But they also invited charity partners from Heads Together, enabling them to catch up with some of those who have been working to increase awareness and spark the conversation this year.

During a group discussion, Harry suggested that young people needed to “lift up their heads” from their phones and iPads and focus on their mental wellbeing.

“He said that his father’s generation used to go out and talk to each other, and now young people are not getting that face-to-face contact,” Ged Flynn of the suicide prevention charity Papyrus, told reporters.

Harry also praised the U.S. for supporting mental health awareness.

“He was talking about how America seems to have a better understanding of mental health because they have a higher level of funding,” Claire McCann, a counselor in London schools for the charity Place2Be, said.

“He feels there should be a collective of mental health charities, a less complicated system for people to access, so that they don’t get lost along the way.”

William and Harry (who said goodbye to his girlfriend Meghan Markle this weekend after her visit to London) joined a session where counselors and volunteers shared their knowledge and were trained on dealing with critical issues, like supporting people who are suicidal and helping young people coping with homelessness.

And Kate spoke with volunteers from an online chat site for those in crisis. The Mix gives young people a helping hand to find their way through any challenge, from homelessness to finding a job, from money to mental health, from breakups to drugs.

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The royals used the party to chat with volunteers and those receiving help from The Mix.

“They’ve done a lot to raise the profile of the Mix,” says the organization’s CEO, Chris Martin. “They are just very, very good with people. They are particularly interested in seeing how they can drive up engagement over the next year or so. They want to see a rise in people being involved and people accessing support services if they need them. There’s a strong belief that the first part of that journey is talking to somebody, engagement with other people.”

Volunteer George Yeorghaki also spent some time with the royals.

“It was good to see them getting involved,” he says. “We spoke about the stigma around mental health and volunteering and getting more people to volunteer. At The Mix young people can contact us and talk about any issue they want to talk about.”

The trio took part in making decorations and building gingerbread houses and met with those doing workshops and talks on homelessness, suicide prevention and counseling.

He adds of the royals, “They have total understanding about the issues around mental health and the importance of trying to raise it in the public eye. They have huge passion and understanding of what we need to do to raise mental health up the agenda.”

Later this week, the trio will start their Christmas break. William and Kate are set to take their children Prince George and Princess Charlotte for their first Christmas at the Middletons’ family home in Bucklebury, in rural Berkshire.

Harry is likely to be with his grandmother, Queen Elizabeth, and the rest of the royal family gathering at Sandringham House.