there is definetly a difference.
first of all, NTR divides in 3 categories, netorare (you being cucked), netorase (asking to be cucked) and netori (stealing someone else's wife/girlfriend).
sharing is more like swinging, kinda of a combination of netorase and netori.
I don't think they are the same but i think that you often see people who like both or hate both whereas it's rarer to see someone who only likes one so it is quite easy to treat them the same.
Sometimes creators use both tags and they make it seem like they can be the same but in the most part the are different but can work together if done properly
Sharing is good, betrayal is bad
Personally... I hate stories where the boyfriend/husband is made a fool of (with rare exceptions). I believe it's much more interesting when there's consent, probably because it's something I would do.
NTR to me is simply vile. I don't like it one bit.
I'm fine with sharing though especially in darker scenarios if it serves a purpose and it's with your character willing to do it.
For example in trainer games where the character youve trained has passed her usefulness... so you throw her to be used by others.
no, but the reasons why they differ could be slightly different depending on how ntr is interpreted. if ntr refers only to netorare, then obviously sharing is different from it. if ntr means netorare, netori, and netorase, then "sharing" (read: netorase) falls under the ntr umbrella, but isn't the whole category, the same way every square is a rectangle, but not all rectangles are squares.
