Love story

Now I'm thinking about a love story, "Perdona si te llamo amor". I'm going to explain the film the italian version, that I watched a few days before.
One day the principal character meets a girl, but she's only (15 or 16, I don't remember), and he thinks that she's beautiful and wonderful. But at the same time he has a relationship with a woman.
He goes out with the teenager in many ocasions, because with her, he can lives the life, and stop thinking in his own work.
Finally he have to choose the routine with the woman or the pure love with the teenager. So this love story in about a pure love, between a man and teenager.