What Should We Do? (Part One: Incest and Meta-Ethics)

Have you ever been torn about what to do in a situation? Here’s one: Jack has fallen in love with Sally. When he is with her he feels butterflies in his stomach and when he is away from her she’s all he can think about. But there’s just one problem: Sally is Jack’s sister.

(the sun cannot express or feel moral judgements, this is an artist’s depiction)

What should Jack do in this situation?