The rarest form of NTR: she cheats not because of some contrivance like blackmail or mind control, but because the affair partner is offering her a genuine emotional connection. Sex with her husband isn't bad because he has a small dick and he cums too quickly, but because their emotional disconnect means he's no longer in tune with her body. Meanwhile, sex with her affair partner isn't good simply because he has a massive cock and can fuck for hours; instead, they communicate with each other, resulting in great sex and a healthier relationship. The protagonist loses his wife not because big penises are magic but because of the characters' actions (actions that are driven by their goals and their flaws)