Why?

It was my friend Yasmin's birthday, and she was opening her presents at our old junior school. Two if my other friends, Lisa and Zoe, and I were trying to run away from her at the back entrance of our old school which was a steep slope. We could hear her talking and commenting on the presents we had got her but as we were running up the steep slope we were all slipping on strawberries and we kept on slipping down. We kept on trying to run up the slope but my friend who we could hear opening her presents popped out and said 'where do you think you're going?'