Anna led Eric back to their home, and (again remembering something about human tradition) took Anna into his arms and swam her across the threshold into their living room. Anna giggled and clung to Eric around the neck, kissing him the whole way. Soon, their kisses grew heated and passionate, and Anna knew that she wouldn't even wait to swim for the bedroom. They were inside now; it was the privacy of their home; this would do.
Anna and Eric floated in the middle of the room together, spinning in one another's arms, until Anna stopped them both with a flick of her tail. Eric looked at Anna questioningly, and she grinned and said, "Don't you move a muscle, mister. I just want to check things out, m'kay?" She kissed her husband again and then lowered herself relative to his body so that she could examine his new fin.
"This," she said, stroking the tube-like spine at the top (it caused Eric to gasp from the unfamiliar sensation, and his eyes to nearly roll back into his head), "is technically not a penis, or a clasper. More of a—"
"A gonopodium," said Eric. Anna looked up in surprise; he quirked an eyebrow and said, "What? Merpeople know their fish."
"Guess so," said Anna. Then she grinned wickedly and gave the outside of the organ a long lick. Eric shivered. "But I think I'm just gonna call this your mer-dick, 'kay, lover?" Then she put her mouth on the end of it and started to give Eric his first proper blowjob.
"Whatever—grk—you—*gasp*—say, beloved."
Anna loved it when Eric called her 'beloved.' She started stroking him more quickly, and humming a little as her tongue teased the tip.
It didn't take too much more of that before Eric was overwhelmed, and he came with a spurt of white fluid that clouded in the water around Anna's face. She grinned up through it and asked, "Well, baby, what did you think of that?"
Eric was reduced to incoherent monosyllables for a while, but eventually he was able to respond, "I think, Anna, that whatever you did—you're a genius." After a beat, he asked, "How do I return the favor?"
Anna thought for a moment. Normally, blowing a guy (especially given that it was her first time in over a year) should have had her turned on as all hell, but she didn't feel particularly "wet" inside. But then again, maybe that was just because she was underwater and everything was wet. Still… "I'm not exactly sure," she admitted, "but let's just take it like we always do and see what our instincts tell us?"
"Okay." And so Eric began to kiss Anna all over her body, just as he was used to doing during the mating time. The fact that Anna was responding the way that she did, moaning and mewling in absolute bliss, even though it definitely wasn't near the full moon, was itself something of a turn-on to Eric. He found his newly-formed penis-analog once again growing stiff and erect, already.
Eric, though, continued lavishing his attention on Anna's boobs, suckling her nipples in the way he knew she liked, the way that used to be the surest way to get her to come and lay her eggs during the mating time. Now, it seemed, he could just keep going at them, and Anna was getting more and more aroused. Until he looked down and saw that her vent was gaping open, the scales parted, and it was, well, larger than it used to be. (Eric actually found that a little off-putting. A mermaid's oviduct was supposed to be petite, just large enough for one egg at a time to pass out of it, and certainly not big enough to penetrate.) But he put that last thought out of his mind when Anna gasped, "Lick it! Please, Eric, lick my mer-pussy—or whatever it is I have now."
Honestly, Anna wasn't really sure what to call it. It didn't have labial folds, and there was definitely no clitoris there, but when she felt Eric's tongue on the scaly outside of her opening, it sure felt good—and when his tongued dipped inside, that was even better. Like a combination of getting her clit licked and her vag penetrated at the same time, somehow. Whatever it was, this mermaid-analog of cunnilingus was absolutely fantastic.
When Anna felt the heat of an orgasm building up inside her, though, she managed to get ahold of herself between her own gasps and cries of pleasure to touch Eric on the head and get him to stop. "Please," she said, through tears of joy, "I want it with you inside me. Cum inside me."
And so Eric obliged. There was a bit of fumbling and some flustered embarrassment as Eric tried to line up his fin with Anna's opening, until she managed to take it in her hand and guide him in. Then they practically fell together, the membrane below the fin somehow folding out of the way so that he could hilt the whole tube-like structure within Anna's oviduct. They both gasped when that happened, and then Anna motioned for Eric to try thrusting in and out, while she thrust her own hips back to match his rhythm. It took some experimentation, but eventually they got the hang of it—they were actually mer-fucking!
Eric and Anna rode the sensations, enjoying each other's bodies, enjoying the feelings that were mostly new to Eric and mostly familiar (if only distantly remembered until now) for Anna. Anna, who had been on the bring already, came first, shivering and shuddering in Eric's arms, while he took several more minutes of pumping in and out before he too went over the edge and released into her.
Then they were hugging each other tightly, glowing, and Anna was whispering into Eric's ear, "I'll bet you got me pregnant, stud. I'll just bet you did."
Whether that was the case or not, they were definitely going to keep trying until Anna was—what had she called it, thought Eric? 'Pregnant'? Good word, he decided. Pregnant with offspring. Gotten with child. Yeah, he could get used to that.