The woman traveling with teenagers was a teacher or chaperone from some school. Boys and girls maybe a hand full of each. I remember a scene where they are in a hotel or wherever they were staying with big staircase and the boys were trying to sneak up the stairs to meet girls and the man was there on couch and turned on light shaking his head no and go back to bed to the boy(s).  The boys kept trying different ways to get to girls.   The man ends up falling in love with the woman chaperone I thought the actor may have been a Cary Grant or Gregory Peck type.   The movie I think was in black and white but not sure and it was in English.