"My dad." She grinned.
"Um... Your dad?" you shyly said as you think about your girlfriend's father, an ex military who has always tried to intimidate you with his big muscles and deep manly voice.
"Aww... is my big boyfriend afraid of my daddy?" your girlfriend teases you.
"C'mon, don't tease me like that, babe." you said as you stop her for teasing you. "It's just that your dad is... ehem... Imposing."
"Don't worry, I know, hun." your girlfriend smiles. "That's what makes it interesting."
"I guess so..." you replied.
"My mom has told me tons of stories about how incredible was my dad." She replies. "And I'm not talking just about the army... I mean, I can see how mature, sexy, and virile he looks despite his age. Plus, I also want to know if my mom got a bigger dick than me."
As you heard what your girlfriend was saying, you became a little embarrassed, she wants to compare your dick with her dad's! "But just one thing I want you to do." you told her.
"What is it, babe?" she asked.
"Could you try not to change me mentally?" you asked her back as she nods and agreed with you. Then, she begins to kisses you deeply while your body starts to change. While you both kisses each other, you start to feel your muscles are growing everywhere, your arms, legs, back and chest. Your height shot up a few inches and your hands and feet got bigger as well. Finally, when the transformation was complete, you both broke the kiss as you open your eyes and you noticed that your girlfriend is smiling at you. "Good to see you, 'daddy'." your girlfriend said while she put her hands on your rock-hard pecs. "Your princess is ready for you."
With that she pulls you on the bed. "Hey, take a easy, honey. There's no need to-" she stopped you as she kiss you passionately and dry-hump you. While you both kissing and licking each other, you both start to strip off all of your clothing until you are completely naked. Once you were naked, you take out of your new cock and put inside her pussy, both of you gasp at the feeling, as you are now completely inside her. After settling a little, she began to move up and down rhythmically. Soon after this she speeds up more and more. As your both start to feel a building feeling, you both hug tightly as making you go even faster. With the newfound speed, you finally hit the spot and she 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/her dad's seed deep within your girlfriend.
Both of you exhausted, you fall to the bed and continue to kiss. You smile at her and breaks the silence. "So, what do you think? Am I bigger than your dad?"
"Well, let's just say I now understand why I have so many siblings." she replied.
"Well, I been thinking." You said with a serious tone.
"What is it? Something wrong? Do you want to change back?" she asked you with a look of concern.
"No, i...it's not that." you answered. "I mean... I like your father's look and I like being with you, y'know. When we're first dating each other, I have met your parents before. Plus, they don't like you being with me, because they think I wasn't good enough for you. And after I transform into your dad, I have been thinking that maybe they're right."
When she heard you saying this, she also seemed so sad. You wish you could change reality, so you will look more like her father and you two could stay together, but what if your personality changes radically and you became the kind of man you don't wanna be. Your girlfriend loves her macho and overprotective dad, but it couldn't be the case with her boyfriend.