They need to stop calling Loki the half-brother
Season 2 episode 20 out right addresses that Loki is adopted yet earlier in the same episode the description caption calls him Thor's half-brother. Adopted, step, and half are not the same things.
Adopted = The child was adopted.
Half = They share one parent.
Step = The child is from a previous marriage of one of your parents.
It's really not that hard but this misinformation could confuse children, especially those of complex family structures.