Tell her to drink the potion

"I would be happy to help," you say to the bashful Morina, "but I am not going to drink a magic potion."

"Um, but, I saved, and um, bought the ingredients, and um, it's definitely right. It'll work," she holds the vial containing the potion out to you again.

"I have an idea," you say and take the vial from her. "Why don't you take the potion. You can grow the cock and that way you'll know exactly what feels good. You'll know just how to please a man that way!"

You open the vial and hold it out to Morina. She seems ****, but she takes the vial and tips it to her lip. The liquid inside disappears into her mouth and she swallows with a wince.

"It doesn't feel like anyth-oh! Oh, my!"

The mousey young human leans against the bed and seems to be experiencing some unusual sensations. She shakes and contorts her face into a mixture of pleasure of pain. A moment later you see a lump taking shape on the front of her robe. It grows and grows until it is clearly the outline of a hard cock.

"I, um, I think it, um, worked," Morina says blushing. "It feels, um, it feels good. Weird, and um, good."

You look at the newly-shaped lump in her robe and wonder what pleasures you should show the shy young woman first.