All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
If this man is a marriageable person to you, then it is not permissible for you to expose your hair or any part of your body in front of him; this applies to whether it is a hired person, a servant and the like. For more benefit, please refer to Fataawa 83033 and 81440.
If a person works as a hired person or a servant, this does not mean that he is among a slave that one's right hand possesses (owns). Islamicly, what the right hand possesses means possessing due to enslaving a person, and this is due to the Muslims imprisoning a non-Muslim in Jihaad (fighting in Allaah's Cause).
The scholars differed in opinion about what is permissible for a slave -if there is one- to see in his female master. Many of them are of the view that it is permissible for him to see from her what a Mahram (i.e. a person whom one is permanently prohibited from marrying due to suckling, marital, or blood relations) is permitted to see from his female relative, and this includes him looking at her hair.
This is the opinion of Ibn 'Abbaas and the mothers of the believers .
Anas narrated that the Prophet brought Faatimah a slave and gifted him to her. Fatimah wore a garment which, when she covered her head, it did not reach her feet, and when she covered her feet with it, that garment was not long enough to reach her head. When the Prophet saw her struggle (in attempt to cover herself), he said: "There is no harm on you: "Here is only your father and your slave." [Abu Daawood]
Allaah Knows best.