Love your post about Loki not having many friends (even though it’s sad).
Who do you think he spent his time with? Or what did he spend his time doing instead?
I tend to agree that Loki must have spent most of his time with Thor on the basis of being raised/studying/training together. As far as canon goes Loki's 'friends' appear to be the ones shared with Thor, though the impression the group gives off is Loki sighing and trying to micromanage the group (to dubious rates of success).
I know the friendships that are written in as OCs typically stem either from the concept of sleeping around (lazy, often comes with promiscuity tropes and a non-OC male love interest) or from studying in magic class (overdone, but the closer to canon option). Both these reasons explain why it's usually women. Both these reasons also explain the choice in characters being borrowed from other media, as fellow mages, love interests, and friends Loki seems to have in the comics also tend to be women.
Considering the general lack of friends and that magic takes work (or being good at it wouldn't be much of a characterisation trait), and that he's shown to overthink and ask more questions than Thor, my guess for what he does in his free time is: spends it alone.
Whether it's for reading or because he spends the time he's not free already with Thor and Thor's friends, that's the image canon creates for me. Which sounds sad but I don't think Loki was sad about it, in Thor 1 he seemed annoyed that Thor dismissed him a lot but the no friends situation doesn't seem to especially grate him.
That he had no one to turn to when family didn't work out was also sad but I don't think he cared about it till the plot of Thor 1 happened and Thor's friends blatantly went against his reasoning to visit Thor on Midgard.
