After Kennedy's death, Ed Klein, an editor for New York Times Magazine and an author of several books about the Kennedy family, stated that one of Kennedy's "favorite topics of humor was indeed Chappaquiddick itself. And he would ask people, 'have you heard any new jokes about Chappaquiddick?'" Klein also said, "It’s not that he didn’t feel remorse about the death of Mary Jo Kopechne, but that he still always saw the other side of everything and the ridiculous side of things, too."
It is always good to have a sense of the irony of life. Unless it was your sister or daughter who was murdered and left in the cold water for fish to feed on.
Stop The ACLU has more on that famous Kennedy hilarity about murdering a young woman who he was trying to seduce.