The Affair is a 1973 American TV movie directed by Gilbert Cates and starring Natalie Wood, Robert Wagner, Bruce Davison and Jamie Smith-Jackson.
Her condition has made her emotionally guarded, but when she meets Marcus Simon, a handsome older attorney, she cautiously moves towards romance.
Both of them are timid about approaching romance - Courtney because of her medical condition; Marcus because his wife recently left him for another man and took their two sons with her.
A family dinner establishes that there is some tension between Courtney's wealthy parents (Kent Smith, Frances Reid) and their two children.
Courtney's younger brother (Davison) is an aspiring artist who disdains the family fortune and lives simply with his girlfriend Jennifer (Jackson).