This is done to enhance the feeling of loss in the NTR game. The hypothetical cheater woman of NTR chooses not beauty, material prosperity and long-term, reliable relationships, but a big dick and good sex. And the fact that she chooses, for example, a homeless man or a fat pimply schoolboy, is an additional spit in the face.
Asuna's situation certainly seems more complicated, she kind of felt sorry for Inoda because of her kindness, but in the end we see that everything is going to lead to her falling in love with a big dick. And sooner or later, Asuna and Inoda's relationship will become public. The bottom line is that a woman in NTR rarely thinks about the consequences.