A Fairy's Tale(1996)

Feeling intimidated when Queen Rowena summons him to her bedchamber, a knight seeks out Gwendolyn the Fairy Princess, in the hope that she can provide him with a potion or spell to improve his performance. After drinking the potion, the knight gauges its effects in Gwendolyn's bed. Monitoring this entire episode via her crystal ball, the wicked Queen Rowena becomes fed up with the Fairy Princess sampling every man she summons, and casts a spell transporting the knight to her dungeon, and another transforming the statuesque Gwendolyn to a tiny little person. The spell will only be broken when a man declares his undying love for Gwendolyn