A cruise on the Pacific goes all wrong, the ship sinks, and there are only 3 Survivors; Damian, Darren and Deirdre. They manage to swim to a small island and they lived there for a couple of years doing what's natural for men and women to do.
After several years of casual sex, Deirdre felt absolutely horrible about what she was doing. She felt having sex with both Damian and Darren was so bad that she killed herself.
It was tragic but Damian and Darren managed to get through it and, after a while, nature once more took its inevitable course.
Well, a couple more years went by and Damian and Darren began to feel absolutely horrible about what they were doing.
So they buried Deirdre.