In order to tell you how I relate to you physically, here is some background info: my last period was in June (I am 53).

That being said, I think a person's libido is 50-90 percent (I don't know the exact percentage, just saying our physical health isn't the only thing that makes sex good) a mental activity.

When you say, "to suddenly just go ppphhtt feels a bit sad." It makes me think. My libido is high when I am optimistic and low when depressed. When things go ppphhtt, it doesn't necessarily make you want to try again the next day, but one week later--it might be great! And you may not have responded simply because there was no "anticipation." I can certainly relate to the Carly Simon song, sometimes I like to talk or hint about the activity for a while (even a day or two) before getting around to it. I think it "primes the pump" in a way. And sometimes we take turns; sometimes only one of us ends up satisfied. Sex is like gambling for me; it is fun when you score big. I hope you try again soon!