OK as per some advice from some members I did file the custody modification papers for my 5 year old son whom my ex husband currently has primary residency of, I also filed for an emergency ex parte order to try and get temporary custody. I was trying to see if I had enough grounds for that, was not sure but tried anyway. My confusion is that isn't the main reason for the ex parte that the respondent not be involved?? Well when I got the denial in mail from the court, there was a CC sent to the respondent(my ex of course)
Which now has pissed him off to no end. I knew that the day would come that he would find out about the custody modification but was this denial supposed to be sent to him??
Now he is taking it out on my son, not letting him see me when he wants. Any advice?

You should indicate what state you are in. As an example, in California ex parte's are not truly done without notice to the other side with the exception of temporary restraining orders (TROs). A TRO is obtained ex parte without notice but that's because they contain allegations of domestic violence and the idea is that by giving notice more domestic violence might be precipitated, or that giving notice might not be possible or practical in the first place. Other ex parte's (such as to modify custody) usually require a minimum of 24 hours notice to the other side (it varies by local rule from county to county as does the procedure for getting one).