Like what you like., hate what you hate, just use your words properly
A love interest (LI) is someone you are in a relationship with, it could mean wife/girlfriend/slave the important part is you have an expectation of exclusivity.
And no they aren't build for you to have, they are built to tell a story, some of these stories will be filled with loss and heartache others with triumph and joy, and the only way we find the stories we want is for people to tag them properly.
NtR has a specific meaning (actually it has 3 specific meanins only 1 in used on this site)
- netorare : Loss of a LI (this is the version this site uses for tagging purposes)
- netori : Stealing someone else's LI
- netorase : An LI being freely shared
I agree sex scenes involving hated NPCs deserve a teg absolutely, so make one, present it.