The wording foregrounds a particularly significant contrast: the desire for chastity stands opposite an attempt at coercion. The comparison intensifies the moral force of the prohibition and draws attention to the severity of the offense.
The unmarked form would state the prohibition without specifying this circumstance. Here the added circumstance can heighten rhetorical impact rather than create a permission in any other case.
Interpretation therefore depends on the purpose of the utterance, not simply translating in as “if” and automatically reversing the ruling.