Autoeroticism is a term that refers to sexual self-stimulation or self-pleasure. The word implies a solitary act and doesn't involve a partner, and it falls under the category of masturbation. The antonym, or opposite, of autoeroticism would be a sexual experience where at least one partner is involved. This could include sexual intercourse, foreplay, or other sexual activities that involve more than one person. These experiences can enhance intimacy and pleasure, as well as bring about feelings of closeness and bonding between partners. While autoeroticism has been the subject of much scientific and cultural discourse, partner-based sexual activities will always be an essential part of human intimacy.