I'm secretly in love with one of my best friends and

I'm secretly in love with one of my best friends and I never told her, She left her laptop once overnight and I looked at her chat logs with other people. And every time the issue of feelings come up I lie to her and I pretend that I never thought about her. She asked me once if I ever had a dirty thought about her and I lied because she wouldn't be comfortable around me if I said yes but I have those thoughts of her everyday