How to get rid of unwanted boners quickly?

im 15 and i sometimes get random boners at school but im pretty iite at hiding it but i would just like it to stop or be able to control it or something, but the worst is when i hug the girl i like, i hug her then within like 2 seconds i can feel it rising lol and i swear she must be able to feel it lmao =\ so when i hug her i got to pull away quickly and obv i dont want to so any suggestions?