Will pushed his twin pricks into Fiona's holes and was enjoying the feeling of her squeezing his shafts. A tingling sensation began in his scalp and on his ears as he continued his thrusting. Fiona reached up and brushed his lengthening hair to one side revealing his ears were also becoming pointed.
"You keep getting sexier by the minute," Fiona giggled and then gasped as Will's cocks grew inside her once again. "Oof. Careful big guy don't break me." Fiona reached up and squeezed one of Will's pectorals and watched her fingers sink slightly into the muscle before he flexed and pushed back. "My big strong Naga."
"And my sexy little elf," Will whispered in her ear. She seemed to like that and wrapped her legs around his waist and arms around his neck. Will grinned and wrapped his hands around Fiona's generous ass and lifted her up. The ease at which Will lifted Fiona up shocked him. He had difficulty remembering that the biceps bulging on his arms were his own, but he also noticed Fiona's arms begin to bulk up from their slim frame. Around his waist Will felt her thighs and calves thicken even more. "My little elf is getting bigger," he teased. Beneath the pair of lovers, Will's massive coils writhed beneath them as he folded the emerald green tail into a massive cushion and lowered them onto it.
"I'm in heaven," Fiona moaned, relishing the feeling of the thick coils surrounding her. 'I do want us to change more though,' she thought and as if to answer her wish, Fiona felt a tingle through her body and if Will's expression was any hint, so was he. Fiona began to feel her legs and feet tingle more intently first, like when your legs fall asleep. She pulled herself closer to Will's chest to look over his shoulder at her feet and watched as they stretched longer and reformed into something else. A claw pushed out from her heel while her toes merged into three longer claws with her nails sharpening into talons. A similar transformation was taking place with her hands with her pinky fingers merging with her ring finger, and her nails forming into claws like her feet.
"Oh fuck," Will groaned, "careful with those. You ever trim your nails?"
Fiona smiled and flexed one of her claws in front of him. "Oh. Nice fangs by the way."
Fiona ran her tongue over her teeth, feeling the wicked points. "I won't bite...much."
Will began to say something, but was interrupted by a strong stretching feeling in his chest, followed by a series of cracks. "What the fuck?" Will looked around desperately in panick as his torso began to stretch taller. Fiona watched as two lumps started to grow below his pectorals as his body stretched. Two points darkened and formed nipples as Fiona realized Will was growing a second pair of pectorals. From his sides two lumps pushed out and formed a second set of arms that were rapidly bulking up to match his original pair. From her position, Fiona also saw Will form more abs, growing from his original 6 into a 10 pack.
"Damn that's hot! I like AH!" Fiona gasped as something pushed hard from her lower back and shoulders. It started small but quickly grew as the growth above her ass formed a powerful tail, each wave of the appendage caused it to grow until it reached 6 feet long and as thick as Will's forearm at the base. Her back was a different story. A pair of lumps pushed larger and larger, but the skin refused to give way.
"Getting a little uncomfortable here. Ah!" Her back surged larger at the same time as Will's twin cocks grew again inside her.
'How big is that going to get,' Will wondered. He looked into Fiona's red eyes and noticed her eyebrows had fallen out and we're being replaced by a pair of raised horn-like growths. "You're so beautiful," Will pulled her into a kiss, wrapping his second pair of arms around her lower back.
As the two kissed passionately Fiona's skin finally gave way and let her huge bat wings unfurl from their prison.