A few months ago, Dazai revealed to his husband Chuuya that he's a merman. It went... well, it certainly went. Chuuya was a little freaked out at first and even banished Dazai to the couch for a few weeks for keeping something like that from him. Now, though? Chuuya is extremely accepting of him. Almost too accepting.
Chuuya, "on a whim," prepped and filled up their unused pool that's been sitting on their penthouse balcony for almost two years now. It doesn't matter what excuse he gives, Dazai knows that he filled up the pool because Dazai mentioned how he missed swimming. Hell, he even bought a few pool floaties so he could hang out with Dazai despite not being a fan of water.
There's something Dazai hasn't told Chuuya about mers yet, though. Every six months, they grow eggs in them. All mers go through it since, technically, mers don't have different sexes. Dazai never lets his get fertilized, which means they dont grow any actual life, so his are usually only the size of golf balls, and he tends to produce less than the average mer, only making around six instead of the usual twelve to fifteen.
Dazai never told Chuuya since it wasn't really a big deal to him, and it's always been easy to hide since the bloat it causes is only visible without a shirt on. Something Dazai didn't take into account is the fact that now that he's spending more time in the pool in his real form, he's spending a lot of time shirtless.
Today, he didn't even bat an eye when he realized his eggs grew overnight, because, again, it isn't a big deal to him. He'll just have to lay them between when he gets home from work and before Chuuya gets home from work, so he has time to dispose of them. So he didn't think much when he went for his morning swim until Chuuya came out to check on him just as Dazai was getting out and gave him a concerned look when he noticed the bloat.
"Hey, Osamu?" He starts, frowning. "Your stomach bothering you?" He asks.