Is it normal for an electric guitar to slide down when played standing up with a strap?
A guitar strap is supposed to hold the guitar without gaining extra slack. You should not have to hold or support your guitar in anyway to keep the strap from loosening. It might help as well to have the adjustment piece above your left shoulder instead of the other way around. When it comes to anything related to guitar (or any instrument for that matter), you get what you pay for – you pay cheap, you are going to get cheap. I’d recommend getting at least one nice strap for $30-40 that won’t hamper you while you are playing. As long as you don’t do anything drastic to your strap, it will last nearly forever. If you take a low grit sand paper (like 18-20) and rough up the underside of your adjustment piece (the black plastic thing in the middle), you might be able to get enough friction so that the strap doesn’t slide.
