Possible Clues:

• Unexpected profession, in modern lingo
• Drop the ___ (confess deep affection)
• Word dropped when things are getting serious, informally
• Awkward word to drop on a first date, informally
• Slangy thing that may be 'dropped' in a serious relationship
• Term to drop in a serious relationship, informally
• What you may "drop" on Valentine's Day, with "the"
• Word that takes a relationship to the next level, slangily
• Something that might be 'dropped' prematurely in a relationship, in slang