When a look of disgust flashes across a loved ones face, how about asking, "Did I do/say something that bothers you?" When they say that its nothing, ask, "Are you sure? I love you very much and I feel that we should be open and honest with each other so that small issues do not become huge problems that seem impossible to solve."
Once a loved one says what is the issue, ask simple questions to learn why, express empathy for their feelings, validation for their feelings, and asking them how they would feel if they were you. The most important thing to remember is to remain loving (i.e., control feelings of anger, frustration, betrail, etc) and compassion. Harville Hendrix, Ph.D. wrote "Getting the Love You Want: A Guide for Couples" which provides more details and examples of how to improve communication with couples.
If a spouse of a JW can figure out how to communicate with a JW's authentic persona, I feel that books by Steve Hassan, Harville Hendrix, and John Grey can help a critically thinking JWs to help a JW loved one's authentic persona to critically think and become stronger.
Peace be with you and everyone, who you love,
Robert