Vipress wasted no time, pushing Rick against the kitchen wall and impaling herself on his erection. Rick was ecstatic by the feel of his dick in Vipress. He tried to grab her ass, but the naga lacked that human characteristic. They continued to passionately kiss and caress as man and snake woman fucked. Rick found it ending too soon.
"Vipress, I'm..."
She responded by kissing him deeply and pressing him against the wall so that Rick penetrated his deepest as his cock began to pump seed into her. Their lips finally broke so Vipress could let out a long hiss of triumph and pleasure. The naga's own orgasm helped keep Rick going.
When Vipress could sense Rick was finally finished, she slid off him and gently lowered the human to the floor where he sat, exhausted by their sex.
"That...was...incredible..." he panted.
"It wasss delightful" said Vipress. "I hope we will mate many more timesss in the future." Then she added. "I think I can feel more chargesss." Rick watched as Vipress' face took on slightly more human characteristics and a nipple appeared on each of her scaly breasts.
"Even more beautiful than before" he observed.
Rick tried to stand up with the aid of the adjacent kitchen counter, but felt dizzy.
"I think that took too much out of me. Maybe I should drink some water..." He took a step toward the sink then staggered and fell to his knees. Rick's legs felt weak, but sitting was uncomfortable; something was wrong with his tailbone. He laid down on the kitchen floor.
"A tail!" exclaimed Vipress. "You are growing a tail!"
Rick reached back and confirmed the naga's observation. He felt a sense of dread. Vipress' transformation had been a surprise, but this was a wholly unexpected and very serious side effect.