Jon, very sorry to hear about this latest development with OM. I agree with the others, all clues point strongly to a PA. If she's kissing him in front of the kids then I assure you that's not all that's going on. I think your boundaries are good, but I also think you tend to backslide and let your W manipulate you. That's got to stop. No more pandering to her, no more flirting, no more laying on the bed holding hands and such. Stick to your boundaries. Leave her be. At this point I would refuse any invitation she extends to you, it's time for some tough love.