I took my children to soft play. My four year old was playing in the 2-4 section and I was watching her and holding the baby. Two girls (approx 7/8) came in and started stacking the big soft shapes, no problem. My dd was playing with a few too, and one of the children went to take them from her (they appeared to be building a den).
My dd started to get cross and I told her not to worry and there were plenty of the shapes for everyone. One of the girls then looked at me, and I smiled. She then proceeded to glare at me and at my daughter, in a really unsettling way
She kept it up for ages, so I asked if she was ok, she then replied 'we want the shapes and she took them'. I explained that she's four, that there were lots, blah blah (she didn't take them). I'm a teacher, and I wanted to say stop glaring and being so mean! But I didn't. The mum came over and heard the tail end and said 'you shouldn't even be in here.'
I was surprised at how bolshy she was in her interactions with me, an adult. She was making me feel uncomfortable as it was so prolonged. And then I wondered whether I should have said anything to her at all! Children can behave so strangely away from their parents, can't they?