Chastity is a virtue.
According to the Catechism of the Catholic Church, a virtue is a “habitual and firm disposition to do the good” (CCC 1803)– a virtue is a decision to we’re faithful, a choice we make over and over despite forces outside us that encourage us to do otherwise.
Chastity is “the successful integration of sexuality within the person and thus the inner unity of man in his bodily and spiritual being” (CCC 2337). So chastity doesn’t separate sexuality from the rest of the stuff that makes us human by denying its existence or by putting it on a pedestal. Instead, chastity helps us to arrange our live in such a way that sexuality isn’t misused.
Chastity “includes an apprenticeship in self-mastery, which is a training in human freedom. The alternative is clear: either we govern our passions and find peace, or we let ourselves be dominated by them and become unhappy” (CCC 2339).