Unless such reservation is regarded as required, one's stance toward human sex acts is contra bonum matrimonii.

Consequently the kind of wrongful sexual choice most often considered by Aquinas is engaging in intercourse with one’s spouse without fides, because one either (i) is thinking of one’s spouse in the way one would think of a prostitute, or (significantly worse) (ii) would be willing to have sex with somebody else if some other attractive person were to be available. Such depersonalized sex acts are instances of willing against the good of marriage (contra bonum matrimonii). This reiterated analys