I'd you keep acting like a nut, your kids will probably gravitate towards someone who at least behaves rationally. If you really want to prevent your kids turning their back on you and going to her, show that you are a healthy individual who doesn't allow their emotions to rule their lives.
It's absolutely irrelevant how they behave in the context of romantic relationships, because it has next to no impact on one's ability to parent. If your intention is to use the children as tools to punish them for being bad at romantic relationships, carry on, you're on the right track. If your main priority is the well-being of your children, perhaps let go of all your anger and resentment.