I was thinking about a story with a King who's kingdom was wiped out by war and he was the only male left who could father children. A witch comes to him with a special potion that would make him endlessly fertile and able to have sex with as many women as he wanted with out rest in between. The only thing was he could not fall in love. If he did, the potion would not work. Of course for 6 months, he is banging eveything in site, but then...