Make him prove it

"I want you to prove what you claim" You said with startling amount of aplomb given your position

"What?" The Dungeon Master responded, clearly taken back "Has everything to this point not been proof enough to you!? What a foolish girl you are. You dare tempt me to show my powers? You know not what you ask!" He regained his temper for a moment, with a disquieting smile

"Fine, if that's how you want to play it. Follow me"

The maze you are in fades to black, and is replaced with an impossibly vast library, unsure if you can even see the ceiling. You find yourself strapped to chair by the wrists and ankles. The Dungeon Master is holding a gigantic book, talking at you, rather than to you "Let's see what is in store for you, my little pet" As he holds the book up for you to see the cover "Now, I don't suspect you able to read, but this is a book of possibilities. Your possibilities. All of the lifes you could have lived in all the ways you could have lived them in all the worlds they could have been lived in. Shall we take a look together?

The Dungeon Master flipped the book open to a random page "Looks like the quaint and domesticated life here..." The library and the chair faded away, showing a busy market street. You travelled as a spirit, while the Dungeon Master appeared material, but had no interaction with the world, his nose still down in his book "You live here with your husband of some years. On the surface, it appears that you have an ideal, if unglamorous life..." You entered the small market building which also served as a house. "People come to your husband for candles, but they come to you for milk..." With this, you finally see yourself. Rather, the version of yourself in this story. Many years older than you are now, and those birthing hips have been put to use at some point in those years. You sat near the back door, with your blouse open, patting the heads of two young men as they sucked on your motherly tits and played with them. Even though you witnessed this as a spirit, you still felt every sensation that the other version of you did.

"There's not much going on here, perhaps there's something else" The dungeon master said dryly, and with a flick of a page, the entire scene changed. Flesh and blood, but with no control of your actions, sitting upon a mighty horse. You and steed both in plate armor, mirrored to a blazing shine in the midday sun. The dungeon master floated alongside you as you galloped down a sloping hillside towards a horde of undead "On the other hand.." he began " you could be a noble paladin, trying to rid the evil that took your one true love away from you" Although the paladin whose body you inhabited showed no outward fear in charging to certain ****, you feel an unmistakable fear "You know what? It doesn't look like this one ends well, let's try something else"

With another flip of the page, you find yourself in royal regalia of some kind, in a ball "Isn't this every girls dream? You could actually be a queen? Legend has it your royal family line is descendant of mermaids, which is why the eldest child always is a beautiful girl. Looks like your kingdom is actually heavy in debauchery. Must have been quite the coronation"

The Dungeon Master flipped the pages again, but than immediately closed it in mock embarrassment, returning you both to the library, with you in the chair
"You and the entire legion? My oh my, even with all possibilities, I wouldn't of thought that for you"

"Is it always sex with you, pervert?

"No, it's normally sex with other people, and mind your tongue, ****"

"Why are you doing this?"

"Because you asked me to, and because you are mine. My question to you is, why are you doing this? Do you seek to further test my patience?"