I have a primary partner, but have gone out on a couple of dates with someone else. I'm not quite sure how to breach the subject of my primary partner, but want to tell them so as not to be a jerk, and let them know what my intentions are/what to expect from me. Advice on this step from those who've done it time and again? I haven't done this before since this is my first open relationship. How soon do you usually do it, and how do you bring it up?