With his legs fully submerged in the saltwater, James felt them drawing together. He grabbed his thighs, trying to see if he could hold them apart, but it was no use. The two appendages slowly became one. His feet flared out into a tailfin, and light blue scales began to appear all over his lower body. But most importantly his penis, now quite erect again and seemingly larger, was still there.
James looked at Sofie. "You did turn me into a..." His voice trailed off and he felt flush. "Something else is..."
Was his voice changing? His chest felt strange. "What's happening to me?"
James felt his hair fall against his shoulders. His chest heaved. He looked down and gasped. "Why do I have breasts?"
Sofie let the towel she'd been wearing fall to the floor. She was visible wet from watching James transform. She climbed into the tub with him. "I think passing transformation on doesn't mean becoming a merman or a mermaid. It means you've become my ideal lover - ideal for my new form."
Sofie could feel her legs becoming a tail as she kissed James and caressed his new breasts. It was weird, but James couldn't deny how good it felt. And once he dried off he'd go back to his normal body. For now he slipped his cock into Sofie for the second time this morning.