I have been doing something dirty to my crush?

I need to talk there’s this guy at my school I have been sending anonymous love letters at school and my best friend delivers them for me. The thing is I used to talk to him, but for the past 2 months I cannot talk to him because I know i am doing something wrong and he has a girlfriend. The other day he came up to me and asked “am I alright?”like a worried look on his face I said “I’m doing ok.” and walked away kinda fast. do you think he’s on to me? he never approached me about the letters though because I try to avoid talking to him. is he afraid too? I heard all his friends know about it. also lately he has been standing near me or very close to me. Like he is watching me. should I think he knows it’s me?
I have been doing something dirty to my crush?
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