Add a separate Preference type that is "Interested," signifying a thing the subject doesn't know if they like or not, but wants to try. The symbol for this could be a grey circle with a question mark.
If you choose to engage in an activity of this type, you should go slow in case the subject doesn't like it (especially in the cases of Clients and Volunteers).
You could also have trying an Interested activity be an Objective. Paying Clients would give Satisfaction for having tried the thing regardless of whether they enjoyed the activity or not.
For dialogue, once you have engaged in an Interested activity, you can comment on it (or ask the subject about it) to see if they want to keep going with it. If the subject really likes it, you wouldn't have to ask to find out. If the subject really doesn't like it, they would tell you to stop.
If a Client or Volunteer tells you to stop and you keep going, Satisfaction would quickly drop and further failure to stop would result in the Client/Volunteer terminating the session.
Customer support service by UserEcho