Some basics.

Paphia's hands glow faintly as the dryad's magic pumped itself into Arianna and Lily's breasts, which swell, visibly pulsing with each beat of their hearts. The pixie and the mermaid's bodies quiver like they're being jolted with electricity, their backs arched is if to present their increasing busts to their fae sister's touch. Paphia herself wasn't a picture of composure, either, as you were slowly moving in her again, your stamina seeming inexhaustible.

"My sister... oooh... she's studying advanced thaumaturgy... she's in the grad program here.... aaaah, that cock's so good...!" explains the dryad between gasps of pleasure. "She taught me... ooooh... a few simple tricks..."

You lean down to suckle at one of Paphia's dripping nipples, tasting her sweet milk and nuzzling your head into her gigantic breasts. You wrap your hands around her waist, holding her tight as you rub your abs against her pregnant belly. You're surprised to feel her shudder in orgasm again as you lavish attention on her nipples. She feels amazingly sensitive in your grasp.

"Aaah.... my tits... they feel... sooooo gooood...!" moans Paphia loudly, almost sobbing with pleasure as her pussy contracts orgasmically around your magically-enhanced cock and her nipples spurt milk into your waiting mouth. Her hands, however, remain clamped to the breasts of her sisters, which are now rapidly approaching her own massive size. Taking a moment to enjoy your mastery over the dryad's body, you bite down lightly on one of her nipples while you pinch the other, hard. All Paphia could do was wail as her voice rose in pitch, her eyes rolling back in her head. Soon she was wailing too high for your ears to hear; you suppose that nearby dogs were on alert, however.

With that pleasurable **** on her senses, Paphia's hands finally lose their purchase on the massive tits of Arianna and Lilly, and the two girls fall backwards, their nipples spurting as they gave gasping moans of pleasure, their hands cradling their pregnant bellies and rubbing at their gushing pussies. You let go of the dryad's nipples, letting her come back down from her pleasurable high, slowing your rhythm, your still-hard cock resting inside of her wet, clutching snatch. For a few moments there's only the sound of the heavy breathing of the four of you as you watch the three fae women gradually collect themselves. Lily half sits, eyes wide as she looks down at her newly-enlarged tits. She brings a tentative index finger to prod her pulsing nipple with milk beading on the tip. She closes her eyes and bites her lower lip at the excruciating pleasure.

You give Paphia a passionate kiss as you slowly withdraw from her, your massive, foot-long cock squirming a bit under your control. Man, this thing was weird... but definitely fun. Very fun. Your lover groans in regret as she feels her pussy no longer full of your cock. As you pull yourself back up to your knees, you can see your lovers' eyes all track to your twitching shaft, their eyes transfixed on it. It's definitely not an accident at this point.

"Hey, girls... do you think my cock is mesmerizing you?"

"Probably..." said Arianna, almost absent-mindedly, slowly crawling over to you, her gaze transfixed on your magically-enhanced cock. "I don't want to look away, that's for certain... and I feel really relaxed."

"Mmm-hmmm! Me too..." said Lily, stretching languidly as she stroked her swollen belly. "It's like... I think it's magic. Making us passive. Docile. Submissive."

Paphia rolled over, staring, along with her sisters.

"And you don't mind, girls?"

"No... it feels good. Sex magic feels good, doesn't it?" said Paphia, her eyes glassy and vacant, but the blush of arousal still in her cheeks.

Well this was certainly something to consider.