The OP starts off with a faulty premise by conflating being a "slvt" with cheating, as JK pointed out.
A lot of the time **** shaming is perpetrated on women who are promiscuous but not unfaithful because they're not in a steady relationship of any kind. Conservative attitudes see the two things as equivalent, but its difficult to actually support this with logic, unless by being sexually promiscuous they're somehow "cheating" on God or some other such nonsense.