Pretty sure this needs a blackmail tag, as she's explicitly being blackmailed into sex at the beginning. Possibly a rape tag too.

1. If blackmail doujins taught me anything, it's that if someone has you doing something dodgy it's better to let it go public rather than let them film you doing something worse.
2. I don't see how this is ntr, she isnt in a relationship with anyone, from whom she is being stolen right?