How do you stay in an emotional state that feels good when you are in the presence of someone who is vibrationally low on the emotional scale?
One method to employ is to assert your boundaries. Your boundary is an invisible line that you draw around yourself that others cannot cross. Sometimes, to implement your boundary you must physically remove yourself from the presence of that person. Other times, you are able to diffuse the energy of the other by being squarely grounded in your own strong positive emotion.
What works for you?