If you are undressing, then it means you must open up more about yourself to others. On the other hand the dream could show your relation with the sexual aspects that are in your life. If you saw somebody else getting undressed, it suggests you to be careful with other people. If you were the one who was undressing the other person, then it means you are willing to know more about that person.
Read more about dreaming of Undress in other dream meanings interpretations.