Divorce is related to Affair. Affair is related to Have. Have is related to Nest. 
Reason is a type of Explanation. Key is a type of Explanation. Key is related to Enter. 
Divorce <--RelatedTo--> Affair <--RelatedTo--> Have <--RelatedTo--> Nest 
Reason --IsA--> Explanation <--IsA-- Key <--RelatedTo--> Enter 