The answers to the clues below will have something in common.

1. Common rule of courtesy
2. Wife and/or mother, usually
3. Owner of rental property, perhaps
4. Musical based on Greek mythology
5. Occasional discount event at clubs
6. Rake or roue, perhaps
7. Serving US President's wife

Answers:

1. Ladies first
2. Lady of the house
3. Landlady
4. "My Fair Lady"
5. Ladies' night
6. Ladies' man
7. First Lady