NTR is when someone you are with, gets with someone else, in your presence.
We, the MC are NOT 'with' this character.
We as the MC do NOT see her have sex with anyone else.
We are not, therefore CUCKED, and this is NOT therefore, NTR.
If you live in a world where you imagine the women you've had sex with, have NOT had sex with anyone else, you are delusional, and snowflake, who should just STFU or go eat a bag of cement and harden the f*ck up.
The only people who will not play a game with a prostitute as a character who happens to be a LI, are sheltered, egomanical, snowflakes. The Dev is under NO obligation to TAG this as having content it DOES NOT HAVE, to appease the whiny little snowflake bitches that are so easily triggered THEY SHOULD NOT BE PLAYING THESE GAMES, like you.