How to stop blushing in front of guys?

I blush at a lot of things, especially when im uncomfortable or embarrassed. But the biggest problems is when it comes to guys. When they talk to me and ask me simple normal questions that everyone asks i ALWAYS start to blush. I know its probably because i never really talked to guys that much but how do i stop from blushing. When i do blush i dont want them thinking that i hav some kind of crush on them becuz i dont. Then everyones asking me why im so red and i start freakin out and turn even redder. This never happens wen i talk to girls. I usually try to distract myself and stare down at my paper (btw this happens at school) but it takes like 30 min or more for the redness to go away. Any other methods to stop, because i really dont want the guys that make me blush think i like them. And please dont tell me to use makeup as a coverup because my face has no acne at all and would like to keep it that way