Prevent element from being dragged on touch devices

Prevent element from being dragged on touch devices

I have had a go at coding my own push menu using css and jquery.

The issue is that on touch devices you can 'drag' .wrapper left and it overlaps the nav element when it is open - it looks terrible!

How would i prevent this from happening? I don't want the .wrapper to be position:fixed.

Here is my fiddle: http://jsfiddle.net/danieljoseph/cL0ej1v3/1/