Is a girl flashing me on webcam considered cheating?

Basically, to make the story short, I have a girlfriend who I love and would never want to hurt. As we are in a long term relationship, we obviously have not done anything sexually recently. The other day, I was on chatroulette and asked this girl to flash me and she actually did. I immediately closed the window, and felt really guilty thinking this was cheating. However, the more I think about it, is this really cheating? I know I would not be comfortable if she had done it to a guy - I understand that and never plan on doing this again. But can this be considered emotional cheating as I clearly just wanted to see someone's boobs - as I have with porn before. I know I will never do this again - but should I tell my girlfriend? I know I should be honest with everything, but is this just a little mistake I made that I don't need to unnecessarily upset her about? I am visiting her soon, and don't know if telling her would be any good for our relationship/