You start thinking about getting some fat on you. You grab your girlfriend and put her in front of the fat chamber.
"Wait what are you-" but before she can finish, you press the button and enter inside.
Once the chamber starts doing its job, you start feeling and seeing how your body expands and wobbles by each second.
You began to enjoy the process to the point you´re aroused just by think of how fat you´ll get.
Outside your girlfriend gets excited to see your new fat form. Immediately after that thought you emerge from the the chamber with wobbling and panting with each step you take.
"You´re enormous!" she loudly says in delight. At this point you weight 800 pound or more, your face has turned into a rounded shape, your cheeks are very round and you feel around 3 chins with you sausage fingers, enormous moobs rest on top of your enormous belly wich touches the floor, your gigantic butt and thighs are just as big as your girlfriends when she got out the second time.
Panting you make or try to make a sexy pose for your girlfriend, all the fat in your body makes it nearly impossible, but it doesn´t stops you from give her a show of your body.
"Someone is enjoying himself a lot, don´t stop shake that ass!!"
Hitting with your meaty your ginormous ass, you make it jiggle in delight as you and your girlfriend get more aroused by the show.
"Huff...This...feels.. soooo gooooood...." you say panting. "You know... why don´t you take me to the big chamber and turned me back to my original size" She says with a lusty smile in her face. "You know, so we can use this lard for something more sexier". She winks at you, making her cheeks to wobble in return.
You think on it, enormously fat couple making sex or maybe you could make you and your girldfriend more fatter while making it after you turned her back to her normal size.