The girl that I am hooking up with suddenly gets cold with me and withdraw attention pretending that we don't even know each other sometimes.

We are participating of a summer school camp for masters and PHDs right now, 100 people are in a research facility for that reason as well.

Sometimes I spot her talking in a very suggestive manner specially with my university colleagues. This triggers anxiety on me and I'm getting little paranoid, even though I try to keep it cool and maintain frame I know she can easily spot the weakness.

Can I get some advice on how to deal with it please?