Class (1983)

When wealthy prep-school senior Skip (Rob Lowe) learns that his shy new roommate Jonathan (Andrew McCarthy) is a total loser at romance, he sends the aspiring young Romeo to the city to learn the ropes before he ruins both their reputations. But when Jonathan is seduced by a sexy cougar named Ellen (Jacqueline Bisset), what begins as a lustful adventure ends with the discovery that not only is Ellen the woman of his dreams - she's also Skip's mom! Rob Lowe, John Cusack and Andrew McCarthy make their feature film debuts in this Mother of all Teen Comedies that’s a “pure fantasy for boys of all ages.” (Boxoffice)