More likely than not a publicity stunt with Halloween coming up soon, but a pop star named Kesha (she spells it Ke$ha - and I still had never heard of her), claims to have had sex with a ghost. Now, as we all know from that great authoritative tome, the "Malleus Maleficarum," this is certainly possible. However, the question then becomes, can she get pregnant. And the answer is yes - but only if the incubus uses semen stolen from a living male. It's all sort of complicated, but fortunately for us, the experts from the medieval ages have figured it all out. And, I'm working on the theory that Ms. Ke$ha is single, since according to the ancient text, incubi and succubi can only mate with single humans, since God instituted marriage and devils are prohibited from having "sexy time" with people in an institution God has blessed.
According to our hero, "I had a couple of experiences with the supernatural. I don't know his name! He was a ghost! I'm very open to it."
Of course she doesn't know his name. Casper apparently doesn't kiss (or do other things) and tell.
A randy young fellow named Prost
Once made passionate love with a ghost.
Upon his orgasm
The pure protoplasm
Said, "You know, I could feel it ... almost!"
I remember a part of it from an issue of Playboy magazine, from about a bazillion years ago. I improvised the rest to suit, and it seems to work.