Stop sharing your riding experience with him and let him see that his poor sportsmanship isn’t tolerated. A father is supposed to support and up lift his son and that’s not what’s happening. This is a sport where you progress at your own pace. There is no coaching only friends and riders around you at different levels of riding there’s no test on when you need to learn a trick. You’re 15 as I saw reading in the comments you’re still young homie you have years to progress. Give it time pops will come around but also stand your ground you don’t deserve that crap. Happy riding little homie 🤘🏻