Yes i say they should see a sex therapist, there are other things that sex is expressing in a marriage, it's the taking the garbage out, help cleaning the house, driving the other person somewhere, being taken care of when you're sick,help with the kids if any, and all the little things we do for the other in the dayitme which make us feel like having sex, that is my opinion. I think it is more in the heart and sometimes that starts in the head as to what leads us to want to make love for all of the good reasons mentioned above.