These panties have a mind of their own

You strip your shoes, jeans, and panties off and discard them on your bathroom floor. You open the fancy box and delicately lift the new underwear out, examining it to see if there is really anything that special about them. You are unable to identify anything of note, shrug, and slip them up your legs. They fit bigger than what you would regularly wear, providing full coverage for your large butt which normally eats all of your regular underwear. As you twirl and push out your butt to check out the fit in the mirror, you are startled by a sultry whisper in your ear, a woman's voice coming from inside the bathroom. "Oh you look fun".

You spin around, eyes wide as you look around your bathroom for the intruder. You pull your shirt down to shield your exposed underwear from whoever had been hiding into your house. But after you have time to calm down and look around, you realize that there is no one there. But you could have sworn...You check the door, finding it still locked, further evidence that you are alone. But you were so sure...

"Hello...down here..." You hear the voice again,but its coming from...between your legs?! You lift your shirt to reveal that your basic white panties are no longer plain white but are now sporting the image of lush, red lips smiling printed on the front. You are positive the lips weren't there before. As you try and figure out how you could have missed such clear bright red lips, you watch them begin to move, accompanied by the disembodied voice echoing slightly in your bathroom.

"Excellent, I have your attention. Nice to meet you! I understand that you may be in a slight state of shock considering you've never had a conversation with your underwear before, but I can assure you that you aren't going crazy."

You stare dumbfounded into the mirror, watching the reflection of the lips printed on your crotch talk to you. You ask quietly, trying to comprehend what is happening, "How is this possible?"

"Why, magic of course!"

You scoff, "Magic isn't real..."

"Hey, you're the one talking to your panties. You can believe me or not. Now, back to why I am here. You see, I was created by a young witch, an aspiring fashion designer, who was looking for ways to infuse her knowledge of magic and her love of creating clothes. She made many different pieces, magic jackets to provide protection, shoes to run faster, glasses to see farther. Mostly party trick stuff from a magic users standpoint. Nothing that impressive, but she was so eager to show her power. She wanted to try something new, something truly epic, and I am the result of that endeavor."

You finally close your mouth, swallowing the hard truth of what is happening to you. "Ok...fine, you are some magicians power trip project. But what exactly do you do...and why were you sent to me?"

The mouth forms a somewhat menacing smile outlined by bright red lips before returning to a warm and friendly tone. "What I can do is up to you. My power is derived from my wearer. For instance, the voice you hear is not my own but how you imagine I would sound. You manifested me, I am already learning so much about you just by being on for this short while. That being said, to truly work I need a more concrete connection. And lucky for you, tonight is one of the best nights for doing magic, the blood moon! That is why you have received me today. If you wear me tonight, I can form a real connection with you and unlock my real power. And tomorrow we can start on an adventure that is guaranteed to be the most magical experience of your life."

"As for why you...let's just say this particular witch knows you and felt you would benefit most from having me in your life. She has a special interest in you which she wishes to remain secret in case you had a negative reaction to her forwardness, which I hope you can understand. Not everyone would appreciate receiving panties from someone. So...will you wear me tonight?"