Relistening to Network Effect again and I think there's a solid case to be made that Ratthi is in a queerplatonic relationship with Overse and Arada (who are in a romantic relationship with each other).
They have a very stable domestic dynamic between them - he helps them work through a disagreement before it can turn into a fight, he passes his leftovers to Arada without either of them having to communicate about it, and at one point is described as co-sleeping with Overse on a couch. (I actually missed both of those last two until recently because Murderbot only mentions them in passing, which suggests that they are a part of the normal patterns of behavior it had observed among them.)
Also there's the fact that the three of them are the only members of the original PresAux survey team to also go on the survey at the start of NE - which makes sense if there's a high level of emotional commitment between them that would make it hard for them to be apart for so many months at a time.
(I only have the audiobook so I can't pull quotes, but the food sharing is at timestamp 5:31:35 and cosleeping at 6:39:13 for anyone who's curious)
