Hmm that's a good question.
Jealousy is an emotion that's rooted in fear and the dreaded feeling that one isn't good enough.
How do I handle such situations with grace and come out looking better
The tactical part is simple:
You ignore it, don't make much of it and carry on.
The only time I might call it out is with a girlfriend if I feel like she's saying it intentionally to annoy me.
But with a chick you haven't slept with, you should ignore it.
That's the tactical/practical part and it's simple.
It's execution, though, relies on handling the emotional response that jealousy triggers.
I like Dr David R Hawkins' Letting Go technique from his book,
Letting Go.
Highly reccomend the book if you want to understand emotions.
Basically, to let go of the jealous emotion (and any negative emotion):
1. Let the jealous emotion arise in your body
2. Do NOT resist it. Hawkins says that resistance is what energizes negative emotions.
3. Refrain yourself from judging yourself for being jealous. Accept that it's what you feel.
3. Allow yourself to feel the jealous emotion.
4. While feeling the emotion, blank out all thoughts.
5. Instead, place all your attention on the physical sensations in your body: the tightening of your stomach, the increased heart rate,...
6. Keep feeling the emotion, no matter how uncomfortable it is. You need courage to face an emotion. The unwillingness to face emotions is what results in repressed grief, fear and anger.
7. As you keep feeling the emotion and focus on the physical sensations, the energy behind the emotion will slowly dissipate.
8. Rinse and repeat until the emotion reduces in intensity.
Best you do it on your own as meditation to release some of that stored jealous emotion.
Next time it happens with a chick you're talking to, follow the same process.
Let the emotion be and it will dissipate.
While the emotion is firing up your insides, gather every ounce of willpower you have to maintain a cool head and get the tactical part right.
Good luck.
I have struggled with jealousy for a long time until I cleared it out.
Retroactive jealousy is another beast I had to take down and seems like you might have too, if you ever get in a relationship.