I love reading Kirk/Spock/Nyota fanfics that depict not only healthy poly, but realistic poly. Nyota and Kirk are going to butt heads AND they’re going to team up and drag Spock to karaoke, get him to loosen up a little. Spock and Nyota are going to worry incessantly about Kirk and try to modify his diet, to ensure he logically and proficiently looks after his body, and Kirk is going to rebel and go out drinking with Bones and complain how they’re worse than Bones is. (To which Bones replies, Dammit Jim, I’m a Doctor, not your therapist. Now drink up, you’ll need a few, living with Pointy.) Spock and Kirk are very intense emotionally, between disagreements and emotionally charged discussions - I’m sure Nyota will pick up on all the little details about Spock’s behavior, reading all the meaning laden things he does for Kirk that are culturally significant to his Vulcan heritage - meanwhile with Kirk, after a good five minute hand holding Vulcan make out session, he becomes impatient with wanting, and snogs Spock senseless, not understanding how significant the kiss is, showing his care in his more exuberant all encompassing way. Nyota wakes up in the morning with Kirk’s hand on her chest, has to peel away from him to go brush her teeth, before she comes back to bed with minty fresh breath to see Kirk limpeting onto Spock, and she kisses them both awake, ready for the day, and Kirk manages to persuade her to spend the day in bed. There’s an enjoyment in being all together, content in one another’s company. They can all get along individually as well, strong friendships and love maintained even though they all have their moments. There’s a cycle of prioritizing different things at different times about each one of them and ensuring that they all look after each other, and keep their little family happy and fair.