DreamsMaster: From the way you phrased it, I’m guessing this housekeeper is not someone you know. If this is the case, then it’s likely this dream character represents an aspect of yourself.
How would you describe this housekeeper? What does a housekeeper represent to you? To me, a housekeeper represents someone in service to someone else. If it were my dream, I might be feeling as if it were my obligation to service my husband sexually. (Remember, this is only my own projection onto your dream, which I’m merely offering as a possible interpretation for your consideration.)
If this line of interpretation doesn’t fit for you, perhaps the housekeeper does not represent an aspect of you, but instead represents another person in your life. Is there anyone you suspect has been having an intimate connection with your husband? Another important thing to consider is what feelings were evoked for you in the dream. Were you angry? Interested? Disinterested?
One more thought that comes to mind is whether or not you have been feeling connected with your husband recently. Whether the housekeeper in the dream represents you or someone else, either way the dream suggests a lack of intimacy between you and your husband. The physical act of sex may be occurring, but is it intimacy?