Boyfriend is derived from Boy. Boy is related to Sex. Sexy is derived from Sex. Sexy is related to Blow. 
Stimulus is related to Shock. Shock is related to Dangerous. 
Boyfriend --DerivedFrom--> Boy <--RelatedTo--> Sex <--DerivedFrom-- Sexy <--RelatedTo--> Blow 
Stimulus <--RelatedTo--> Shock <--RelatedTo--> Dangerous 