Prince George had a memorable “you can’t sit with us” moment with his cousin, Savannah Phillips.
During the playdate, which included running around the field and playing with a Slinky, the 7-year-old daughter of William’s cousins Peter and Autumn Phillips playfully pushed George, 4, down a hill when he attempted to sit next to her.
Though George wasn’t injured and regained his balance, Savannah wasn’t unscathed as she was scolded by mom Autumn immediately after.
Also during the polo event, Savannah was spotted ruffling George’s hair when he wasn’t looking. While she had some fun teasing the future heir to the throne, Queen Elizabeth‘s great-granddaughter appeared to show more affection to Princess Charlotte.
“[Savannah] sat with Charlotte in her lap,” an observer told PEOPLE. “She hugged her and balanced her on her knee.”
But George also had some fun on his own.
“He leapt right into it. The first thing they did when they left the car was slide down the hill on his bum,” the onlooker said. “He was peering over some hoarding around the side of the pitch, grinning at the others, who were messing around with him.”
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George’s push down the hill comes after Savannah wanted her cousin to keep it cool on the Buckingham Palace balcony when she promptly placed her right hand right over his mouth when he started to giggle.
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“Savannah started it by pretending to conduct as the national anthem was played and George joined in the fun. But when Savannah realized it was probably not what they should be doing – maybe William said something to them – she stopped George from saying any more. He was either saying the wrong thing or giggling,” another observer told PEOPLE.