Things causing me to become overly competitive?

i've been in this situation before..and your friend sounded like my friend, who would gloat when i did bad, but i would not do the same in return..what i did is stopped sharing my grades..just say "i don't like to share my grades anymore..it's private and no one else's business but mine" or if you don't want to say that just lie and say you got like 99% or something really high aha..or just say "i did very well, thanks" hope this helps :)