My ex bf brought his new gf to the place where we met and had our first kiss. He shared it all over social media. It hurts. How should I react?

Because whatever happened there with you plays no significant meaning towards what he has with this new girl. Maybe the place is nice. So he took her there because he likes it. He's moved on. And although you think of it as your spot once it's a public place it's everyone's spot.