Meeting the Ex, or Conversely, Meeting the Replacement

I consider myself to be a calm, rational, easy-going person. Hey, whatever works, you know? I'm down with that. That is, until the past or possible future of the guy I'm dating makes an appearance.

Intellectually, I reassure myself that obviously, this woman is an "ex" for a reason, and that if there was anything between them, they would be together now. And if he looks at, or shows interest in, another woman, I can give it some detached perspective: hey, he's still a red-blooded American male, it's nothing personal, and I don't need to compare myself to someone else.

Now, emotionally:
Look at that dumb bitch. He must have been severely drunk when he hooked up with her. Or fat. Maybe he used to be fat and he had no self esteem? But man, am I a major upgrade. OK, that's enough chit chat ho, move along.

Oh don't give me that fake smile, you shit bag waitress, I know what you're up to. I'll smack those veneers right off. Your ass doesn't look that good, and he's an ass man. Have you seen mine? You could bounce some of that loose change from your tips offa it. Maybe I'll call the restaurant after we leave and tell the manager about your serious drug problem. That's enough chit chat ho, move along.