As you continue thrusting harder and harder, you begin to notice your girlfriend's body is going to change, you first saw her breasts growing into double F cups and so as her body shapes into a beautiful hourglass figure, then her face and voice are changing into someone a little bit mature and very familiar of your mother's image. And finally, 10 seconds later, when her transformation was complete, the person who is on top of you and makes love with you is no longer your girlfriend, but the almost perfect naked body of a beautiful woman you just happen to call mom. Your 'mom' (who is your girlfriend morphs into) looks down at you and smiles, "Well, that was a wild ride, wasn't it?" Your transformed girlfriend asked with your mom's voice and her new attitude.
"Oh my god, that's incredible, you turn into my mom." you impress as your girlfriend morphs into your mom during sex.
"What are you talking about, sweetie?" your former girlfriend asks as she's confused about what are you talking about.
"Oh sorry, mom. I was spacing out," you reply as you forgot that your girlfriend turns into your mom mentally.
"Teehee... it's alright, sweetie. Mommy understands, now let us finish this." And then when you both finished conversations, she continued to move up and down rhythmically. Soon after this your former girlfriend in the form of your mother speeds up more and more, you sit up and grab her hips making her go even faster. "Oh god, I gotta cum!" You shout.
"Oh my baby boy, cum into me! Give your mommy your seed!!" she shouts as she demanded you. With the newfound speed, your girlfriend/mother finally hits the spot and forces you deep inside of her where you finally explode. You hold her tightly against you and kiss her gently as you continue to release your seed deep within her. Both of you are exhausted, you fall on the ground as you both lay there kissing each other. After a time you pull back and look at your girlfriend who is still in your mother's form, she smiles at you. "Wow, that was the best sex we ever had, sweetie. I think you're way better than your dad. If you don't mind, you wanna go another round with mommy?" your transformed girlfriend/mom asks.
"Hehe," you laugh as you reply, "Well, I'm always ready whenever you are."
Your girlfriend/mother smiles again and the two of you go back to kissing.