"Woah, look honey. What do you think? I'm fat, and I'm a guy."
"Of course, you are, babe." You chuckles as you look at the fat guy who is your girlfriend wearing the skinsuit.
"Come to think of it, when I'm wearing this costume, I can see my fat belly body that covers the little guy," your girlfriend explains. "Plus, my voice even changed as I'm in this suit."
"That's because you are completely a different person, babe," you reply back. "But anyway, how does it feel to be a guy?"
"Well, how should I put this? It feels kinda heavy and chubby." she or rather he exclaims. "I mean, when I'm wearing this suit, I feel like, tired as hell, and suddenly want some snacks and sleep."
"Yeah, I know what you are talking about." You smile when you see your former girlfriend in a fat man's body as s/he's examined it. "But still, you got some boobs."
"Yeah, the man boobs and jiggling body." Your girlfriend responds as s/he seems to like it. While your girlfriend examined her/his new body of this man she's wearing, s/he suddenly feels like something poking on his/her belly. "Oh dear, something is poking me." S/he suprises.
"Nah, it's just your fat cock that get erected, babe."
"Oh really? Teeheehee... Damn, I totally forgot about the little guy." s/he shyly responds as s/he looks down at his/her first fat dick. "So this is what you boys feel like to be erected."
"Well, let's just say sometimes we could help ourselves." You reply while your former girlfriend keeps standing there and watches it. "What's wrong, babe?"
"Well, I think... it's kinda hard to do this on myself, but would you... um... help me out? I know it's kinda weird, but..."
"Don't worry, I'll help you out." You come closer to her/him as you start to touch her/his penis to do the handjob. With that, after you're grabbing her/his fat dick, you start to jerk off for your girlfriend rhythmically. "Ooooohhhhhh... so this is... how it feels... like..." Your girlfriend moans. "Oooohhh... that feels goooooodddd... I... I... think I... gotta..."
As s/he can't hold any longer and release all of her/his seeds all over your face. "Oh, sorry, honey. I couldn't help myself." S/he apologized.
"Nah, it's fine." You wipe off his/her cum on your face and break silence. "Babe,..."