Your girlfriend fells that and moans in pleasure, feeling your shaft penetrating her over and over again. The two of you soon started to kiss one more time while you banged her. You soon proceeded to go down her C-cup breasts and being to lick one of them. She big her lip and grabbed hold of the sheets, gripping it tighter. Both you and your girlfriend keep on fucking each other and enjoying the bliss. Suddenly, you feel something while you keep fucking your girlfriend, but more than that, you are just taking in the moment, finally getting to enjoy being inside your girlfriend, to finally fuck her.
Your girlfriend moans in pleasure, but the first noticeable change was a crack in her voice. You don't mind about it, but continue to fuck her. You look at your girlfriend, at her big bouncing chest, and notably how big they are. Are they bigger than before? You stare at her boobs as they grow more and more to the point where her size are now G-cups.
"Hey,... don't slow down," your girlfriend yelps between her moaning.
"Oh right... sorry." While a bit distracted, you make sure you keep going. You continue to stare at your girlfriend during which her boobs are now bigger than before. Somehow it turn you on even more as it's even hotter in a way she wasn't used to in the C-Cups.
It wasn't just her breasts. Her thighs were thicker. Overall she was more curvier. And also she's getting taller and older.
"I said don't slow down, young man," your girlfriend uttered. It wasn't her voice. It sounded like a mature sultry, sensual feminine, and deep voice. It's turning you on. Why is it turning you on even more? Are you really that excited?
It doesn't matter, what matter was you have to finish this. With that, you thrust inside your transformed girlfriend harder and faster as you can, no matter what. "Oh yeah,... that's it, baby. Harder! Faster! Give Mommy a Best FUCK!" With that you cum to her as you shot the load of semen into her pussy.
After cumming, you gather your bearings and look properly at your girlfriend. Her hair was blonde and cute short girly pixie, now growing longer into a long, wavy hair with a brunette color. Her young and cute face has reforms sharp, sexy angular face she looked like an older woman who is the same age as your mom.
"Babe? Y... you... you..." You ask with your confused face while look at your girlfriend who is now a MILF for no reason.
"What's wrong, sweetie?" She asks with a motherly attitude. "And what did you call me? Babe?"
"Babe, you... you're changed. You just change when we have sex. It's worked." You reply.
"Change? I just don't know what you are talking about, but it's not good to call me 'babe' at my age, young man. You prefer me as Ma'am, understand?" Your former girlfriend in the MILF responds with her new attitude as she didn't aware the change. What are you gotta do now?