Why My Male friend acted faulty?

We where friends for over 3 months , we work together than all of sudden he says we can't be friends because he got a girlfriend and its disrespectful. We can only be work colleague So I agreed and walked away from our friendship but 3 days later some other guy asked him if his single and he said yeah. The guy tried to fix his daughter. I am hurt that he lied and never respected our friendship. How do I behave with him at work. Everytime I see him it makes me upset. It makes me feel like something was wrong with me.

Why My Male friend acted faulty?
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