Have a look at this thread:
One of the most common toys in the bdsm world are the various types of clips and clamps. There are a huge array of different types and styles, so what's the difference and what if you can't access these bdsm toys? So answering my last question first, if you can't or don't want to buy bdsm...
www.kinktalk.com
It contains what you need to know about getting started with them. As for the zipper, that looks amazing in porn but as
@Nurse Pervert has said that is next level pain so you'll need to get plenty of experience under your belt first.
Also keep in mind that everyone is different, so don't compare what you've seen with what you can do.