The Bachelor and the Bobby-Soxer (1947) on Netflix

The adolescent Susan Turner is a fashionable and spoiled teenager that lives with her tough and uptight sister Margaret Turner, who is a judge. One day, Margaret has to judge the artist Richard "Dick" Nugent, who is a reckless and wolf playboy, for a fight in a nightclub and she dismiss the case. Richard leaves the court and goes to the high-school where Susan studies to give a lecture of modern arts to the students. Susan has a crush on Richard and she breaks up with her boyfriend Jerry. She interviews Richard after the lecture and during the night, she lies to the portlier of his building telling that she is going to model for Richard and she sneaks in his apartment. She sleeps on the couch and when Richard arrives home late night, he does not see her. Meanwhile, Margaret and her friend, the district attorney Tommy, are seeking out Susan. When they find her in Richard's apartment, they believe that she has been seduced by him and Richard is sent to the jail. Margaret's uncle Beemish, who is the court psychiatrist, convinces Margaret to release Richard; otherwise Susan's crush would not stop. They make a deal with Richard forcing him to date Susan to diminish her passion. Richard dislikes the situation but has no other way out of the problem. While dating Susan, Richard and Margaret fall in love with each other; but Susan is a pain in the ass for them.