Why do guys act so different in front of there friends ??

You're just young. It's an immature response to an issue of self-esteem. If they were confident in how their friends viewed them, then they wouldn't have to act differently. Of course there will be subtle differences in how people interact with others, but if it pisses you off then it's likely he's pulling a complete flip and is acting the opposite at times of how he should.

This is not supposed to be normal behavior, whatever these others are saying. Don't put up with it, at least not for too long; some guys grow up faster than others.

If your friends clown you for acting like yourself, you should be able to tell them to f*** off, and then they should be able to say, "Fuck you too , mang!" and then you should all still be able to laugh and drink a beer. Otherwise you're not friends.

You have it backwords they act different when they aren't around there friends. Just like they act different with, different with there family, different alone. You just have yet to really be close to a man how is secure in who he is and consistent with who he is regaurdless of who he is around. They are out there.

because we are guys :( my ex had the same problem as you she hated when I changed when I was with my friends. Really it all comes down to we all want our friends to respect us and we don't want to look like a bunch of panzy's in front of them. So really try not to take it to personal or try to make to much of it we are guys and yes I did think about it when my ex had a probablem with it and it is not fair for you girls. So all I can suggest is talk to the guy about it and let him know it bugs you and go from there. Good luck!