Actually no it is the opposite. All NTR is a type of cheating but not all cheating is a type of NTR.
Like when a woman has a relationship with another man without wanting to leave the original man or preferring the another man then it just cheating not NTR.
if you are not sure about the meaning of a japanese hentai term, vndb is usually a good place to check
from VNDB:
You must be registered to see the links
but since we are in f95zone, its better to also check the tag rules of the site:
Tags Rules And List [Updated 2024-01-29] "Netorare [Designed to cause jealousy by having the romantic interest involved with someone other than the MC.]"
so basically its more about MC's jealousy and feelings, it doesnt matter if the love interest still want to be in a relationship with MC while cheating with others. even in rape where the love interest hated everything, the situation is still considered as ntr type c.
hope this don't get removed since its kinda "off topic" from the game thread to be honest. we should never have needed to talk about the meaning of ntr in a game thread.