AFAIK
Netorare is just as someone said, partner one (usually female) cheats and partner two (usually male) doesnt like it, but cant leave the relationship/situation for one reason or another. Blackmail, being tied up/held by other people and forced to watch, or economical/emotional reasons why they cant leave partner one.
Netorase is when partner one sleeps with other people with partner twos consent and liking it. This would be cuckold. But i don't think it needs partner two to be humiliated, so a stag/vixen situation would probably be called netorase as well.