Some bits, particularly those with a jointed mouthpiece, whether snaffle or broken mouth curb, look nice and soft to us. Horses can absolutely not find them nice or soft and hate them.
The nutcracker action can pinch the corners of the mouth, poke the roof and some horses don’t like the jointed parts moving separately, it unsettles them. Ones that are fidgety anyway can really get going with them.
IME, horses get their tongues over bits by nervously playing with bouncing the moving parts around with their tongues or trying to spit the bit out. Once they realize doing so " changes the subject" with the rider, they can use it as an evasion. You absolutely can’t ride one withthetkngue over the bit because A) it hurts and B) you have no control and if they panic, you up the creek.
You can tie the tongue, it’s a PITA, or figure out WHY the horse is doing it and fix that. Maybe just adjusting the headstall tighter, maybe the bit is too wide or narrow, maybe a different bit.
Try adjusting the headstall and some different bits on the horse, borrow them if you need to but don’t spring for a new gimmick bit assuming your horse will find it comfortable and not try to spit it out or fool with it. Even if they can’t get the tongue over, horse may hate it…seems a bit of a mouthful from the picture.
Most of my personal horses have been deemed " hot" by others and had far better luck with non jointed mouthpieces and sides. I also prefer a port with most, for sure fussy mouthed horses. It eliminates many issues like bouncing the parts or getting the tongue over it trying to spit it out. They seem more secure without the moving parts.
Just a thought, be sure you fall back on a little bit theory, like the difference between a broken mouthed curb and a snaffle and that a jointed or non jointed mouthpiece and side can be found in both. And both can be equally harsh if it’s the wrong bit or it’s too wide or narrow or the headstall is not appropriately adjusted, especially if it’s too big.
Think about it.
