Hook-up Vs. Girlfriend Material?

I was recently talking to this guy who I met in a professional context and I thought we really hit it off, had similar values and that there was chemistry. Then, he pretty much tried to sleep with me in his office... I was shocked! We'd never even been on a date! Guys, what behaviors or actions give you a vibe that a girl might be easy? I think I must have given him the wrong idea about myself.
Hook-up Vs. Girlfriend Material?
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