Depends on the person getting cheated on.
Roughly netorare will focus more on the couple that is having an affair together, rather than the married or dating couple whose relationship is being violated while netori focus or the cheater steal their relationship.
Netorare[ ] Definition: The protagonist or a love interest of the protagonist enters into a physical relationship with a third party and comes to prefer the third party over time, consequently either cheating or breaking up the original coupling. If the protagonist is the one doing the seducing, use "Netori" instead.
Netori. Definition: The protagonist forces a love interest who is already in a relationship with a third party into a physical relationship, and the love interest comes to like it over time, thus either cheating or breaking up with their original partner.
Netorase is the partner are actually wanting and willing to make her to have sex with other people. So cuckholding. Cheating is the other is unaware they're cheating. The neto terms have the partners knowing they are getting cheated on in some way. Forced or willing.