There was a story about 2 roommates who get upset with each other.
One of them is a witch and turns the other into a sex doll and her friend into a dildo. She ends up using her friend as a dildo in disgust because her libido is too high. It might be the one call Wicked With Barbi, but I am not sure.
A guy comes by and has his way with the one turned into a doll and then the roommate donates the transformed doll to a teenage kid.... I think.