I love the idea of them becoming parents in the late! Twins is an amazing idea, I'm very much vibing with the hc they at least adopt one daughter. They'd be perfect girl dads, showering her with love and a lot of whimsy. I especially loved that idea bc I can see her being the center of attention of them AND her uncles and basically being a little princess who's also a demon (like I hc Rintarou's little sister to be). And actually, her aunt would be the cool aunt who is an extra parent figure, more maternal, and SunaOsa turn to her when they are a bit clueless when it comes to girl talks and she handles it well. Aaaah it's a hole I will dig with you hardcore! Now if they've got twins, I'd like for them to have both a girl and boy and for the boy to have maybe a more shy demeanor but go on a rampage led by his sister and SunaOsa are always right behind to teach them better with love (Rin encourages shit too much lmao). Imagine their son at Onirigi Miya's counter, listening to his dad's rambling about something while the daughter is out shopping with their aunt and aaah I love their family. Also they both know Osamu is weak as fuck to stray (that's why they have a cat, Osamu got it from the dumpsters behind Onigiri Miya years before they were born, now it's an old cat) and the two little devil find a stray dog and literally bring him back home when Rin isn't there to stop the madness! YES! Keep it cooooming! (Also please please don't take it the wrong way bc it's not your fault i'm not super outspoken with my no gos but I do nooooot interact with m-preg at all for personal reasons, so please let's go with adoption thank you!! <3)