**Background:**  
I recently heard the saying from a doctor: "men are motivated to have sex when they ***want to*** feel good and women are motivated to have sex when they ***already*** feel good".
 
(In a side note, such a difference would help to explain why males might not understand female sexual motivation.)


**Questions:**

* Do any scientific studies support the claim that males have greater sexual motivation when they want to feel good (or are experiencing temporary lower subjective well-being) whereas females have greater sexual motivation when they already feel good ?
* If so, what is the reason for this difference?