Far above the ocean, the moon a waxing gibbous and three days from full, the "atmosphere" of the merpeople's underwater world changed just a tiny bit. You didn't feel any different yourself, but you could see it in the way the mermaids behaved. All of the females of at least a certain age, from the waifish mergirls to the well-endowed mermatrons, were all exceptionally spunky, upbeat, and often openly flirtatious (more so than usual, that is).
The males didn't seem to be particularly affected by the lunar cycle, you noticed. (That, you supposed, could explain how Eric wouldn't know about it. Maybe the mermaids just normally didn't talk about it with the mermen they didn't intend to mate with. Served the jerk right, if that were the case.) What few mermen there were in the undersea colony (and there were very few indeed compared to the maidens, something like four or five females to every male) went on behaving as they always did, most of them friendly enough and a few indifferent at the worst.
There were even couple of net-weavers, Jake and Glaucus, who had invited you to have drinks with them after the first mating-day of the cycle, so that you could celebrate and get to know each other and maybe discuss the possibility of taking up either their own craft or learning net-fishing. Setting aside just how exactly merfolk went about getting drunk under water (you were almost as curious about that as about mer-sex now), they seemed like the kind of decent guys you could be buddies with. You also learned that neither of them were actually planning on doing any mating this month, which surprised you a little. Why wouldn't they take the opportunity, if it only came around so often? Well as it turned out, Jake hadn't been claimed by any females yet (which you took to mean that he wasn't in a relationship with anyone), and Glaucus, who was decades older, did have a wife but wasn't out to spawn more kids. "But you young'uns go and have your fun, now," he would say when you brought up the subject. "You and Clia should enjoy that sort of thing at your age."
That was a funny way to put it, you thought, but that was also exactly what you were planning on doing. So, no argument from you there.
Anyway, on the appointed morning, you woke up as usual in the seaweed-and-sponge bed you shared with Clia, within the larger home that you now shared with the rest of her family. She was groggy and slow to wake up; when you kissed her neck, she could only roll over and groan, mumbling quietly, "So full."
You reach down and feel her belly, which seems slightly − bloated? Swollen? "Are those eggs?" you whisper, mostly to yourself.
Clia's eyes are still closed, but she giggles. "No, silly," she answers quietly. "It's food. I had to stuff myself full yesterday. Didn't you get my note?"
You reach over to the coral night-stand and pick up the scratched shell. "Uh, yeah, but − I can't read your written language yet."
Clia rolls over and faces you, eyes wide open now. She's embarrassed. "Oh, of course! How stupid of me!" She looks apologetic and kisses you full on the lips.
You notice right away that it's even more arousing than you've become used to. Her lips on yours, your chests and tails pressed together, even your normally-insensitive tailfins flicking at one another, it's intoxicating, and you don't want to pull away. But eventually, reluctantly, you do. "So, what was the feeding frenzy for?"
"To keep up my energy," said Clia. "They say that laying really takes it out of you. Not that I would know from experience . . ." She blushes and looks away shyly.
"So you've never − ?"
"Nope." Her smile turns coy. "I guess that makes me a virgin."
You look down at your tails, the fins gently wafting together in the water. "Technically, me too, as far as this body is concerned."
She takes your hand in hers, gives you a quick kiss, and says, "Then let's go figure it out together." She lifts off the bed and hovers above you, waiting for you to follow.
"Where are we going?" you ask.
"To the kelp beds," says Clia. "That's where it happens."
You figure that she knows better than you, so, off you go, swimming together hand-in-hand.