In the BDSM community, a Cosmo is a submissive who takes on a very subservient role. They may be required to do things like cook, clean, and run errands for their dominant partner. A Cosmo is someone who enjoys being helpful and serving others, and they often find fulfillment in doing so. While some subs may view this type of role as degrading or unfulfilling, others find it empowering and enjoy the feeling of being useful to their partner.