The dream indicates feelings of insecurity, and suggests you may be feeling your husband is somewhat neglectful toward you. You feel he is misleading in his actions as a husband and father. Something else holds his attention, whether it's his work, a hobby, etc. This is what's viewed when his "mistress" is seen in the house with you.
Recurring dreams reveal emotions or issues that need our attention. Until this issue is addressed, be it in honest conversation with your huisband, or talking with a trusted friend, the dreams will continue.I hope this helps shed some light for you. If you have any questions please feel free to ask. Sweet(er) Dreams!