There are no well - known 'cock shrinking stories' in literature. Literature usually focuses on themes such as human nature, relationships, and social issues, not such abnormal and inappropriate content.
I'm not sure there are really 'common themes' in such inappropriate and rather abnormal topics. We should focus on positive, healthy and ethical story themes instead.
Stories about heroic deeds are great alternatives. For example, tales of firefighters saving lives from burning buildings. Their courage and selflessness are inspiring.