Hey is fast becoming the silent language of lovers. It speaks volumes though only one word is spoken. It's a deep expression of emotional feelings from one or both parties. It is softly spoken and sometimes can't be heard by 3rd parties present but the two minds that are connected. Mostly used when there's a barrier to loving each other openly, often used in electronic messaging to call each others attention or to just say "I'm missing you " while playing safe in case the message drops into wrong hands, then it can be easily classified as "an ordinary greeting"