Keep in mind that this happens to every jumper at some point. Each time he refuses, it makes you anticipate a refusal more and more. Without realizing it, you change your seat and the horse is slightly aware that you dont think he will - and then he doesn't jump! It's an ugly cycle, I know! The way I look at it is, you cant be afraid to fall of, since it is very possible to get flung. Then, you have to put yourself in the state of mind that he WILL jump, and he will because you will cue him and TELL him to. It doesnt sound like there is a pain issue here, hes probably just getting away with what he can. You must get your mind right before approach. Have a good attitude and don't consider a refusal. Just push push push with confidence and a strong seat (that will help incase he does a sliding stop as well!). Also, be relentless. Don't end on a bad note unless you have to, and just keep trying until he realizes that you mean business. It would be far better to be left behind because you were too focused on getting him to jump, than to let him get away with this consistently. Once he is jumping consistently, then you can worry about your jumping ettiquette. Good luck. I have been there many times and fully understand your frusteration!! He buldges out how? He may just be stiff and doesnt want to bend, if he is bulging the way I am picturing. Stretching before riding?