United Kingdom, April 17 -- Caroline Kennedy "laughed so hard" at Grace Gummer's portrayal of her in Love Story: John F. Kennedy Jr. + Carolyn Bessette.

The FX show retells the tumultuous relationship between the businessman and the publicist - which ended in the pair and her sister, Lauren Bessette, dying after a light aircraft, piloted by JFK. Jr. crashed into the Atlantic Ocean off Martha's Vineyard, Massachusetts, in July 1999 - and the impact it had on the Kennedy family.

Caroline, 68, and her 33-year-old son, Jack Schlossberg, saw a clip of one scene, which he did not reveal, and they found humour in how she came across as having over-the-top behaviour - insisting that is not how JFK Jr.'s sister acts.

Appearing on the latest epi...