Jon thought for a few minutes, then he decided to try something much stranger. The thought occurred to him, if he could swap body parts, could he swap body parts in different places. he thought about how to word his new thought and said it out loud.
"Swap my waist down, with her neck down."
In the instant that Jon finished his sentence his view shot up by five feet. He looked down, from his waist up he was normal, but from the waist down was the entire body of the giantess. He gingerly moved his massive feminine arms, it happened so naturally he didn't even have to think about it. He lifted his legs, one at a time and removed his shoes, caressing his new feet and feeling strong and strange pleasures as he felt every inch of her flesh as if it were his own.
"I can't just swap back, I have to play with this." He moaned slightly.
Going all the way he stripped her body completely, fortunately she wasn't wearing a bra or panties, he stretched his massive body out across the small couch and started to caress her breasts. He bent down and used his hands on one bringing himself close enough to suck on the massive nipple as her hands moved down and started rubbing her pussy. Jon moaned loudly as he slowly felt his hips buck more and more, naked flesh rubbing against the fabric of the couch. It wasn't long before Jon reached climax, but he didn't stop at that first orgasm. Lost in a sea of pleasure, the new and massive expanse of flesh urging him onward, he spent the rest of his night masturbating with the giantess's body. He would swap back eventually the next morning, but for now he was going to ride this orgy to it's last.