Loki's loyalty extends to two people, and even at that it's debatable if he even actually cares for those people; Loki loves Frigga and, even though he said hurtful things to her in Thor 2, he clearly regretted it and grieved Frigga The second person he shows some form of loyalty to is Thor, though Loki's actions and driving power changes on a dime Lastly, or more accurately firstly, Loki is loyal to himself and to power; he craves power, the ability to control, and fearful respect. None of this is reflected on him being "Team Iron Man”, being overprotective of Tony, and being angry at Wanda for her actions; in fact, based on his history of being a mage and judged for it, he would probably view Wanda with a smidge of respect for one, leaving the safehouse in CW, two playing mind games back in AoU, and three for the sheer power her magic offers. Then he'd go on to fight any and all Avengers in sight Because that's who Loki is: he doesn't stand with a team or partner, because he has no reason to trust anyone but himself Loki (and Thor, though that's a discussion for later) would not choose a side because they're able to stand on their own two feet and recognize that such arguments are, quite frankly, ridiculous and they have more important things to think about Loki is Team Loki