"You know I don't normally think you're stupid, don't you?" Loki asked, expression a little sharper than it normally was, like he was just looking for an excuse to properly frown at his sorcerer. "But if you actually think I'm going to just stand here for hours on end while you're maybe dead behind a portal, I might need to reassess my previous judgement."
Was Loki angry about this?
Marginally. Magic worked weirdly sometimes and time travel without the support of an Infinity Stone or a lot of experience was generally a bad idea.
Was he also very curious about what was behind that portal? One hundred percent. There was always some part of Loki that was actively hoping for trouble, and oh, the fact that there were multiple portals that could mean catastrophe right in front of him was... tempting.