Composing a Poem

I was sitting on the bench by the lake on a sunny day, watching a clump of tiger lilies dip and bend toward the water. They look thirsty, I thought. Just then, a young man on a jog stopped, took off his shoes and stepped into the water. He cupped some of the lake in his hands and cooled himself off. As he began to climb out of the blue he noticed the flowers. He scowled at them, and kicked a spray in their direction.

Why would he do such a thing? And how could I describe it in a poem? I could...