I saw this on television, possibly during the 1970s or 1980s. It was in color. The movie was about a single mother and her troubled teenage son, maybe 12 years old and they both lived alone together in an apartment. I can’t remember if it was Chicago or New York City, but it had that sort of ambience. They lived in an apartment building. The son was very jealous and possessive of his mother and did not want her to date or have boyfriends. When she started seeing a man, the son plotted to have her boyfriend murdered. During the movie, he decides to make a pass and try to kiss this other older teenagers girlfriend. The older teenager is chasing the young teenager down the street.  A young biker with a leather jacket, confronts the older teenager to protect the young kid. They both become friends.As the movie progressed, he has a relationship with an older high school girl. The story continued, and he was very determined to put an answer to the relationship. His mother had with her boyfriend.  He decides to plan a fire in the apartment building to kill his mother‘s boyfriend. The biker, is very concerned as the kid climbs up the fire escape to start the fire. The biker friend makes a call to the police.The movie continues where the mother is trapped in the apartment. Her son is screaming somebody please help my mother, but it’s too late and she ends up getting killed in the fire. The teenager now is in a rehab rehabilitation house for troubled children.  The movie ends where the boyfriend goes to visit, but he’s not permitted to see the teenager. As his mother’s boyfriend is walking out, he glances up and sees the teenager, staring at him through a window. The boyfriend is waving at him, acting silly to try to get him to laugh. And that’s how the movie ends.