You wanted to tell your girlfriend to turn back into a girl. That should be what you would want, right? But something makes you pause. You can't deny how strongly attracted you are to your girlfriend in her new male body, and especially to that cock. Just thinking about it again makes your own cock strain almost painfully against your pants, which doesn't go unnoticed by your girlfriend who smiles looking at your bulge.
"Well, I can tell what you are thinking about..." He says playfully while wiggling his own erect cock back and forth.
This nearly sends you over the edge. "Fuck. I know this sounds crazy, but I can't take it anymore. Please stay as you are and just...fuck me!" At this you begin tearing off your own clothes. Quickly shucking your shirt and pulling off your shoes and pants. By this point, your girlfriend has walked up to you and pulls off your boxers, freeing your cock standing fully erect.
You whimper softly as his cock brushes against yours. You take it in your hand and relish in the feel of its heat and stiffness. An intense need overcomes you to have his cock plunged into your ass. Just 5 minutes ago, you were a straight male who never thought about doing anything like this. Now, there was nothing else you wanted more than this throbbing, hard cock in front of you!
You lock eyes with your girlfriend for a moment and then spin around and bend over the bed behind you, lifting your ass in the air towards your girlfriend's cock. "Take me! Now!" Even just saying those words to him makes you even hornier as your ass practically tingles in anticipation.
Your girlfriend doesn't waste much time and grabs the sides of your butt while lining up her manhood with your virgin hole. "You asked for it babe!" He says while slowly moving his cock into and out of you, then picking up the pace and thrusting a little faster and a little harder. You gasp and moan in pleasure. Never have you felt anything like this! The feeling of your girlfriend's hard cock pounding your ass has you seeing stars. Eventually, you can't contain yourself any longer. You howl with an intense rush of pleasure as you come and spray your seed all over the bed beneath you. At about the same time, you hear your girlfriend grunt loudly and moan as you feel his cock spasm and pump liquid inside you.
You both collapse on the bed together, totally spent from the experience. Your girlfriend gives you a mischievous smile, and you wonder what he wants to try next.