"...my friend's 16yr old, cross dressing brother, Marty."
"Wait, Marty?" your girlfriend responded, knowing just who you were talking about. Marty was your friend Luke's little brother. Marty had been dressing as a girl secretly since he was about 8, and just two years ago he came out to his brother. His brother was a nice guy, and promised not to tell their parents under the condition that he could refer to Marty as "little sister" when ever he wanted. Marty agreed, and continued on with his cross dressing. Sometimes he would even show off to you and Luke when his parents weren't home, and you had to admit he made a pretty cute girl. However, there was little time left for reflection as your girlfriend's changes had started.
It started as all your girlfriend's clothes suddenly vanished. Next her body began to change. Her breast, which were a nice C cup, deflated down to just barely an A cup. Then her hips thinned out, and her butt became rather flat. Her height didn't change much, nor did the length of her hair as Marty already had shoulder length hair. However, after she lost an inch, her hair switched from the light blonde it was, to black. She then covered her face with her hands as she felt the changes move up there. When it was done, she removed her hands, and she looked just like Marty, if Marty had a vagina. That last part was fixed quickly as her clit quickly enlarged as her ovaries dropped down into a sac and became testicles. With the completion of the penis, her changes where done, and she was now he.
You girlfriend stood there silent for a moment, but then moved to a mirror to see her changes. After a few minutes she turned to you with a stern look on "his" face and said,"Okay, you better explain why you chose this. I thought you said you weren't going to waste your chance? Or is this not a waste? And why does Marty have breast?"
"Alright, alright" you start,"I'll explain why. First thing you should know, for about the past two or three years I have become a little bi-curious. Now being with you, I never tried anything with anyone cause I just could never cheat on you. So now that we have this room I figured I could try a little experiment with you as the guy, that way I am not cheating. Second, I chose Marty because I am comfortable with him. To be honest, I think he is very cute, and when he cross dresses he makes a great looking girl too. I figured that since he made a good looking girl, it would be easier for us to go out and eat in public. Heck, Marty goes out all the time dressed as a girl, just we call him Mary when he does. Besides, I don't think I could do anything sexual with a masculine guy anyways. As for the breast, well Marty has been taking hormones secretely for the past year. He hasn't told his parents yet, but he wants to actually become a girl."
"Well" your girlfriend says looking a little suprised,"I guess I can see what your saying, but I still wish you talked to me about this before you changed me. Oh well, what's done is done." She takes one more look in the mirror. "I do see what your saying though. The hormones he is taking are doing a good job on his body. If things keep going this way, he will be a cute girl someday."
She then turns back to you with a smile on "his" face, and begins to walk over to you. "Anyways, I hope your ready, cause I ain't going to let you live this one down. You better give me one of the best lays I ever had, or when it comes to my turn I might not be so nice with your transformation." With that she plants a long sweet kiss on your lips. You know it's still your girlfriend in there, but right now you just decide to enjoy the moment as things are now. Just you and the very feminine boy named Marty.