Serena's crazy crush

This story takes place after Pokémon XY episode 26 "A Battle by Any Other Name!". Serena is worried about the heads up warning Miette gave her about Ash. She goes by herself to a river, at night, and stares at the stars. It's her way of soul searching. Ash eventually joins her and tells her about his history as a pokemon trainer. He also talks about his history with other females.