I've been dating this girl for a while. She had a notebook that she claimed was full of doodles, and told me not to look in it. Naturally, I did. It was full of personal notes, not doodles. Should I tell her?
Lying about anything is a slippery slope
What will the next lie be?
But.... If your relationship is Only Physical then who cares.....
If they were doodles then there shouldn't have been a problem. She lied first, but you should rise above that. Tell her what happened, and apologize.
I think you should admit you looked. Honesty is important and you violated her privacy.
I think you were wrong but if you plan on being a more honorable gentleman you may want to keep this indiscretion to yourself. Proceed with caution.
KEEP YOUR MOUTH SHUT!
You should be honest. Would you look through her phone?