I'm in DBT and they know I have suicidal thoughts almost every day, but also I've only gotten close twice in my life and both more than 20 years ago. It's just part of my reality which subsides greatly when my life doesn't suck. When I've mentioned it to therapist and pdoc they ask the obligatory questions and are satisfied with my explanation. Thinking about it (without making plans) is a lot more common than a lot of people realize I think.