Haha, I've been wondering the same thing, but then I realize that 20 years ago, I was that dumba** who thought I could love him out of being an angry drunk. 20 years later, I knew that my amazing love had the capability of standing by as he became an angry abusive and dangerous drunk. That's how much power was in my love. And that's how much power is in the love of the dumba** ladies your ex picks up.
I pity them (my AXH is the same way, picks up cute blond 25-year-olds and God only knows what they see in him?) -- because you know what they don't.
Either way -- like you say, the more he's getting around, the less he's bugging you. I have the same experience.