Came from a scene/life experience that actually happened, but I thought I'd change it a little and make something more interesting out of it.
The stream of water shimmered in the fountain, reflecting the glow of the lamp above. The night was dark and calm.
"Are you ready?" She handed him a penny.
He nodded.
"So are we going to do the thing where we shout out our wishes in unison or should we keep them secret?"
"Well... It's not real or anything... And you already know what I'm going to say anyway..."
"Yeah, but to stick with the formalities -- okay whatever."
She looked at him. He gestured for her to go first, and she hastily took the first turn.
"I wanna pass my university entrance exams!"
Flick. Plunk.
He paused, pensively, as he watched her coin sink into the shallow pool.
He sighed. "I want a woman to love me."
Splash. She could see the individual flicks of light on the surface of the fountain, energetically luminous from the wishes they made.
She turned her glance back to him, without saying anything.
...There is already a woman who loves you very much.
That was lovely. Very heartwarming.