When guys are doing handstands and stuff with basketball shorts, what should we do about them flying up?

When I do gymnastics at school, it is nice to wear some basketball shorts because they are comfortable and light, but when I do handstands or headstands or anything like that, they fly up and show my white legs lol. What should I do about that? I am an average guy that will not wear those tiny shorts or almost speedos like Olympic gymnasts wear, so I wear basketball shorts. I like to wear like plaid shorts, but they are a bit rougher and not as light. Is there anything that I could wear under that wouldn't be like tight bikers' shorts, but that would be light that would just stay up?