It can barely be called an NTR game. It just introduces a character as your girlfriend, and then you can grind some boring mini-games to unlock technically animated pictures of her having sex with (another??)man.
There is no dialogue, story, or anything to build up, or cause feelings of jealousy etc.
Imagine going on sad panda or other sites, open a random folder with picture of a character having sex, but before you watch the pictures, there is a caption saying "btw this character is your girlfriend" That's this game.
Also, the majority of the sex scenes you unlock, does not even involve the mc's gf.