Sorry if I Love You (2008)

Alex Belli is a 37 year old advertising executive whose fiancée Elena has just left him, and who is having difficulty at work trying to think of a good advertising campaign for a new Japanese product. Niki is a bubbly 17 year old student. She has three best friends with whom she shares all her problems, and an annoying ex-boyfriend Fabio who is set on getting her back, but Niki's not interested. One day on his way to work, Alex collides with Niki on a city street. They soon begin a romance, despite their 20-year age gap.