i think my fantasy is seeing a small female character having her vagina impaled upon the penis of a large male, being made to take to the hilt a big cock thats far too large for tiny pussy, and as a result of that, she dies, literally from getting fucked to death upon a giant insertion she was far too little to survive, bonus points for it being wholly consensual and shes enthusiastic about taking this collossal dick in her hole, able to handle the pain of being torn apart on the inside by pure algophillic masochism (shes in love with the guy killing her, is unwaveringly and fearlessly suicidal, and wants to die in exactly this way).

This is the fifth path that human x fairy monstergirl sex could go down, rather than "she grows big", "he shrinks small", "she stretches out to take him", or "they do outercourse only (sacred bodyjobs!)", theres also "he goes inside her as is and just completely destroys her (but at least one participant would consider it worthwhile)".