Your partner is a recreational marijuana smoker, and it bothers you. What do you say?

If it bothers you, be open and forward about it.

Try to be specific in stating why his or her cannabis use bothers you and provide examples to illustrate your perspective. For instance, you might say, “You're always high when my parents come over for dinner, and it's embarrassing for me.”

Indicate whether you would like to see abstinence moving forward or a reduction in use to a certain frequency — once a month or less, for instance.

The next step would be to work together to find an agreeable goal and follow it. If your partner has difficulty reducing or quitting, you may encourage him or her to seek formal treatment at a local community health center.

— Dr. Ryan Vandrey, associate professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, who studies the effects of cannabis use

If your objection is coming as a surprise, introduce it gently. Don't say, “Stop now, or I'm leaving,” but rather, “I'd like to talk about your habit. Can we find a way forward here?”

Try to explain your feelings, such as, “When you smoke, it's like you're not really in the room; I feel ignored.”

If this is an ongoing issue, be wary of negative emotions. So, “I hate you for this” won't get as good a result as “I feel uneasy” or “I'm concerned.”

Make a genuine attempt to understand why your partner acts the way he or she does. Useful questions could be: “What could we do to make it easier for you to stop?”

A monologue about your feelings will leave your partner overwhelmed and defensive.

And be prepared to offer support. You might be dealing with an addiction. Good phrases are “It's great we're talking it through” and “I know it's hard for you.”

— Susan Quilliam, relationship psychologist and author of “How to Choose a Partner”

Social Graces is a series asking two experts for advice on awkward situations.

Andreea Ciulac is a freelancer.