awkward

Weird and mostly boring day at the start))
These guys,they never change,staring at my boobs......geezus.....
At the last lesson (english btw) i sat (finally) with crush-san and asked him to come with us to eat pizza...he declined,saying the'll fell better without him. As a normal person,i tried to cheer him up,and said it'll be more fun if he comes too.....then,he was like''ya inlove?'' and i was like ''with who?''
And then.....the awkward time began.....he said ''with me'' ....and of course my tsundere mode turned on so i said '' pfff...you crazy?'' and the lesson ended....he asked me if i'll go home with him,but well,i had an appointment with my friends so the reply was ''no''. It would've been a good idea to go with him....we could clear the things up,but i made a promise after all,so i couldn't go with him.
Don't wanna go to school on Monday....it'll be awkward.....
What should i do? I can't say i like him,it'll be trublesome for both of us...so i need a reason..omg.....
Advice?