I've been on both sides of that conversation (haven't most of us?) and I can only tell you what I would like to hear: absolute honesty. Don't rush into it and blurt it out and, of course, having the conversation in privacy and when there's time to talk is a must. I personally try to avoid the "we need to talk" as a starter to the conversation...that puts just about everyone on the defensive. Just be honest about your feelings, what SPECIFICALLY isn't working in the relationship, and that you want to move on. Be prepared for the other person to try and convince you to stay and know in your mind whether you're willing to consider that IN ADVANCE.

Best of luck...it's not an easy conversation, to be sure, but honesty's always the best policy.

M