You got it spot on, I think me and my partner have literally said that Three’s ideal state is tending the grill at the neighborhood bbq.

When Neo comes into their life they basically become an older sibling forced to take on the role of a parent on the spot. Neo’s home life sucks, they don’t really have a place to even live, so having them around kind of forces Three to step up and start learning to listen better to the needs of others.

When Neo is introduced to Eight it kind of solidifies the relationship as something parental-adjacent, to the point where Neo is saying stuff like “but Eight said it was okay!!” and whining when the two won’t let them have zebra cakes and soda for dinner.

As for after that, I think it’d be super cute for them to adopt and, after working everything out with Three’s SBS dilemma, I think they’d make good parents. Then Three finally has a justification for their exhausted dad energy (and wardrobe).