Cotton scanties under cycling shorts defeat the purpose of cycling shorts. On a bike, step-ins chafe and breed bacteria. They are an invitation to infected saddle sores. I know a young woman who actually had to pay a visit to the Emergency Room after 2 days of riding with panties under her shorts. The doctor told her "One more day like that and you'd have needed stitches."
Needless to say, nothing comes between me and my chamois.
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Religion is a good thing for good people and a bad thing for bad people. --H. Richard Niebuhr