When I've been riding my pony hes taken up the habit of just opening his mouth :S I'm guessing this is as a result from my riding. What am I doing wrong and how can I stop this??
It could be lots of things, not necessarily your riding.
Check your hand position, make sure that your thumbs are on top, as if you're holding coffee cups, have the rein between your ring and little fingers, held above the knuckle nearest to the fingernail. This allows you to make adjustments with small gentle movements. Check that your hand position is not fixed but that you move your hands with the horse's head movement.
Look carefully at the bit, especially if the problem has just arisen, there might be a rough patch which is annoying the horse.
Have the horse's teeth checked as any irregularities there can cause irritation against the bit. Your dentist will also be able to advise about a suitable bit to fit the horse's mouth shape.
Please do not start to use a drop/flash/grackle noseband to close the horse's mouth without finding out why this is happening.
Hope this helps and you find a sloution soon
Also in your siggy the chestnut stood still is quite overbent, if this is the chap with the problem it may be he is uncomfortable? Don't wish to be mean but it could be worth considering?