Peter Grill and the Philosopher's Time Vol. 7 (manga)

Peter Grill is caught in the crossfire between two elven sisters! Vegan and her older sister Fulltalia whisk him away to the elven village, where he’s cursed with forbidden erotic sensitivity magic. The sisters are about to drain him dry! But why are they seeking his seed anyway? And what caused them to turn on each other? And most importantly, how will Peter wriggle out of this latest mess?!