Many couples come to couples therapy to talk about a problem in their relationship. Sometimes what brings them is a sexual issue but often that is not their main issue. So will you have to talk about sex? You may be asked about it initially because it is a part of the larger picture of your relationship and the therapist may want to know what is going on with the two of you in a number of different areas, including sexual activity. In most cases with most therapists, you will be the ones to set up what is talked about in your therapy, that is, what is important for you to talk about is what will most often take “center stage.” So, no, in most cases where you don’t bring sexual issues as your problem then that won’t be talked about, and if you don’t want to talk about it or don’t see a problem in that area, you will not be talking about sex in couples therapy.
If you or your partner wants to talk about a sexual issue, then it will be something that comes up and will most likely need to be addressed in the work, just as any other issue you or your partner brings up. If the therapist feels that you need to talk about it and you don’t, you don’t have to talk about it—it is your time, you are paying for the sessions, and you don’t have to talk about anything you don’t want to talk about. If your partner wants to talk about it and you don’t, then it becomes an issue of what the couple needs to talk about, not just what you (or your spouse) wants to talk about. So if your partner wants to talk about sex and you don’t, it will come up in the work, and both sides of the issue will have to be addressed to help the couple with it. If the therapist wants to talk about the sexual relationship and neither of you want to do so, it is possible that it would be important for the therapy to spend some time on the sexual aspects of the relationship. But if it is not making sense to either of the couple that you are spending time talking on sex in the sessions and that is not what you want, it would be good to say that to the therapist. If the therapist is spending time on things that are not important to the couple, tell the therapist that she/he is off track. As well, people don’t come back to therapy when it does not stay mostly focused on what they came for.
In summary, don’t be overly concerned about having to talk about sex (or any other topic) when you go to couples therapy if both of you don’t want to talk about it. And do make sure to talk about and work on the topics you do want to talk about.