A guy I met has a girlfriend and made me look like a fool in front of my family I feel like a fool help

So? This happens all the time... women do that too, you just met him, there exists no expectation of mutual exclusivity until you have an engagement ring.

So you just don't see him again. That's life... you move on... you aren't OWED anything... and if you feel some NEED to get even... you lose any moral high ground you had, AND you would belittle yourself.

How long had you know the guy before you took him around your family?

It happens. You now know he has a girl friend so leave him alone. To try and get even or stay with him would really make you look bad.

A guy I met has a girlfriend and made me look like a fool in front of my family I feel like a fool help

How were you to know if he didn't say anything? Had you been actually going out with him at all or just met him? If you've just met him, did you start telling people that you liked him before knowing more about him? Or did he keep knowledge of his girlfriend from you while acting interested in you? Two different situations.

One... if you jumped ahead after just meeting him, and without knowing more about him, then now you know to get to know someone better before allowing any feelings to develop too quickly.

Two... if he allowed to you believe that he was single, then he is the one who is a fool, and I would feel sorry for his girlfriend.