"Sorry to bother you, but after this trip I'm a little thirsty." Melanie said
"There are some bottles of juice in the fridge, you can get one if you like." Beth said
Melanie opened the fridge and saw some flavors, and she chose the grape one, which she took and went to her room drinking its contents on the way. She barely finished taking the juice when she started to feel strange, there was a pressure between her legs and, looking down, she saw that she was getting fat very fast. Her clothes quickly gave way under the pressure and her entire body was becoming more and more spherical, taking in her arms and legs, and even got a shock to see a flaccid one foot dick hanging between her legs. She noticed that despite the increase in size, she didn't seem to be getting any heavier, which was odd.
The shock of what was happening slowed Melanie's judgment, so her body was already a perfect expanding sphere, having absorbed her legs to the knees and arms to the elbows, when she finally screamed.
After the scream, it took Beth a minute to run to the bedroom door, at which point Melanie's body was a sphere 6 feet in diameter from which only her hands, feet, breasts, head and her new dick stood out.
"What did you do?" Beth asked when she saw her.
"I did nothing. I just took the juice from the fridge and this happened." Melanie said
"Holy shit, I left one behind." Beth said seeing the empty bottle in the room's trash can.
"One what?" Melanie asked
"I thought you might know that at some point, but I couldn't be so fast and that way. It turns out I'm a witch and what you took was not juice but a transformative potion." Beth said
"What? A real witch?" Melanie asked
"Exactly. I intended to tell you after I got to know you better and in case we got along. I took out the potions I had in the fridge and took them to a safer place in hopes you wouldn't drink them by accident, but a bottle ended up being left behind before I noticed. I should have gotten the regular juice one instead. It's my fault for reusing juice bottles to store the potions." Beth said
"So you can make me go back to normal, can you?" Melanie asked
"I can empty you, but right now I can't turn you back to normal. This potion has a temporary effect and is only for me to use in moments of leisure or with trusted friends, but it only has to be taken a little. You've downed the entire bottle and are clearly suffering the effects of an overdose, one of which is the potion with a temporary effect becoming permanent." Beth said
"Am I going to spend the rest of my life being a ball?" Melanie asked
"No, as soon as I empty you, you'll go back to your normal size, but from time to time you'll fill up again." Beth said
"And there's no way to get me back to normal permanently?" Melanie asked
"There is, but it won't be easy. To combat the side effects of an overdose of a potion you need to take the antidote, but the antidote has to be very powerful and in those cases the ingredients are very rare and difficult to get. I checked my book on antidotes and I can say that I don't have any of the necessary ingredients." Beth said
"I knew I should have been wary of cheap rent. In less than an hour I'm already in trouble." Melanie said
"Don't worry. This is my fault and I will take full responsibility. I will do everything in my power to heal you." Beth said
"Well, and you said you can 'empty' me. So do it soon." Melanie said
"OK. I'm going to need to be a little rough, but you're going to have to bear it." Beth said and then she rolled Melanie out of her room, making a motion with her fingers that made the door stretch for her to be able to pass, and led the new housemate into her own room. Once there she opened the middle door of her wardrobe, pushed her clothes aside and then opened another door which was at the back, and with the same signal as before to widen the passage she rolled Melanie through it.
From what Melanie had seen from the outside, on the other side of this wall should have been the outside of the house, but instead there was a stone room with a cauldron in the middle and few small windows, apart from various materials certainly related to witchcraft.
Beth stopped Melanie next to a bucket with rune symbols around the edges, then she took the swollen woman's cock and stroked it, making it hard.
"Do you really need to do this?" Melanie asked
"There's no other way to get all this cum out of you. You won't be able to do this on your own." Beth said
"Cum? Is it all cum that's keeping me round like a ball?" Melanie asked
"Exactly. The potion you took, taken in correct doses, makes a female grow a dick and her whole body becomes a ballsack making the girl just like you when they are full of cum, but the effect should last a maximum of six hours. As I explained in your case, due to the overdose this time is not valid for you, who will continue to be a walking ballsack until you die or, being optimistic, until I manage to make the antidote." Beth said
"How embarrassing. How could I get myself into this? And I'm not blaming you, I noticed things that could identify you as a witch but I didn't believe it was possible, if I did I would have fled immediately." Melanie said
"That's why I didn't tell you right away and put the rent low, this rumor that witches are always evil. Witches are rare and even for one it is difficult to cross paths with another by chance, this makes it difficult to make friends and makes life lonely." Beth said
"Sorry I..."
"No need to apologize, just trust me." Beth said as she continued to stroke the two foot hard cock between Melanie's feet
The two women remained silent until Melanie felt a strong pulse in her cock. "It's almost time, looks like you're about to come." Beth said and it was no different, Melanie came and her cum shot into the rune bucket.
The amount of cum coming out of Melanie's cock was truly unimaginable and her body was withering away in the process, gradually returning to its normal size and form. Melanie was sure that the bucket was enchanted because even with all the cum that fell into it, it never filled up.
It was almost 30 minutes of orgasm before finally the orgasm ended, so Melanie was practically back to normal, except for the cock that now occupied the space between her legs, and underneath there was neither a ballsack nor her vagina.