Back in his youth, the old man had wanted to marry his first cousin, but his family forbid it. Many decades later, the old man has raised three children (two boys and one girl), and allows his son and daughter to marry and have children. Soon, the sister is bored with brother #1, and jumps in the bed of brother #2.

One might think that the three siblings are stuck somewhere on a remote island. But no -- they are upper class Europeans going to college and busy in the social world.

Never do we see a flirtatious moment between any non-related female and the two brothers. Never do we see any flirtatious moment between any non-related male and the one sister. All flirtatious moments are shared between only between the brothers and sister.

The weakest part of GLADIATOR was the incest thing. The young emperor Commodus would have hundreds of slave girls and a city full of marriage-minded girls all over him, but no -- he only wanted his sister? If movie incest is your cup of tea, then SUNSHINE will (slowly) thrill you to no end.