my crush

so, I'm gay and have a crush, but..

so as i stated im gay but i have a problem.. i have a friend (best friend lolz) but she has a cousin who goes to the same skl, i thought at the start of the year when we became friends this wouldnt be a problem. now we are at the half way+ mark. i have started to have a crush on him.. and idk how to tell her.. im thinking i js dont tell her but idk, any help or recommendations?

thanks!! bye <3 sending love, have a good day xx