Is there a double standard here that I'm not aware of? Girls only?

Me and a few guys were hanging at this guys house and we were being really immature; burping, farting and telling gross jokes! Anyways everyone ganged up on this guy and one guy farted on his face, everyone was laughing even the recipient! Here is when it went south, I had to fart too, so i told the guys to keep holding him down and I did it too!! He didn't yell at me at first but I found out later he was really hurt by my action. I know he thinks im hot and has a crush on me and from what I'm getting at was really embarred from what I did. I'm sorry that I hurt him that way but can you explain why it's any different when his friend did that to him first??