What actors and actresses appeared in First Lesson - 1989?

You're likely thinking of the film "Firstborn" which was released in 1984, not 1989.

Here are the main actors and actresses who appeared in "Firstborn":

* Robert Downey Jr. as "Casey"

* Christopher Plummer as "Phillip"

* Teri Garr as "Lisa"

* Sharon Stone as "Bonnie"

* Sarah Jessica Parker as "Molly"

* Ethan Hawke as "Phillip's son"

There is no film titled "First Lesson" released in 1989.