Erin stood there, wearing absolutely nothing. The sight of her naked breasts gave John an erection. There was also no hiding the large green fish tail and massive two-feet-long three-feet-wide caudal fin that she balanced on.
She was dripping wet and there was a puddle of water under her caudal fin.
She balanced fairly well, waiting for John to say something.
He didn't say much for a few minutes. Finally, he managed, "W---wow."
"Well," said Erin, "I know what you're thinking. 'She didn't tell me this on-line.' I... don't like to talk about it. I think you can see why."
"What --- how ---"
"Are you still interested in dinner? I'll explain everything if you want, but I'm getting hungry."
"Wait... is... this isn't a joke? Is that... is that real?"
"It's real, John. I'm sorry. I'm half-fish. I know you expected a normal human girl, but, well, this is what I am and I can't change it, so you deserve to know it upfront," she said as her caudal fin flapped against the floor, causing ripples in the puddle beneath her.
"Geez," he said. "How...?"
"Are you still interested in joining me for dinner? I'll tell you the whole story over our date, if you're still willing to give me a chance."
He looked up at her. She looked very sad, not ready to break into tears, but sad like she had just lost a boyfriend. She was still very pretty overall, surprisingly graceful for being a literal fish out of water, and seemed really nice on-line. His last few dates had been disasters, with each girl more psycho than the next; even if Erin was a half-fish, she was more normal than they were. Might as well give her the benefit of the doubt.
He got up from the couch. "Alright. Let's do dinner, and you can tell me how this happened to you."