And let's face it - what's going to happen (legalities notwithstanding)?
New partner is going to turn around, laugh heartily and make some sort of snarky comment along the lines of "your ex is a loon" and "wow, is this one bitter much? Never got over you, huh?"
It's just the nature of the beast. You can have the best intentions in the world, but the bottom line is that these are adults, they're going to do what they're going to do and simply because it IS the nature of the beast, likely to stand up for "their man" against what is likely going to be perceived as sour grapes.

