I tell people about shit like this all the time. I'm kind of outspoken, and VERY brash, I have been told girls have a regular system of what needs to be said before they start getting offended, and they've had to invent a completely new one for me, because as one girl put it"You're the king of saying fucked up shit." This does not make me an asshole however, as when I say REALLY fucked up shit it's a joke, otherwise they know I'm just being honest and telling them what most people have a hard time saying.
In fact, I have a lot of friends who actually enjoy this blunt honesty. As soon as they get over the fact that I will say what everyone else doesn't, and I'm not an asshole they like me.
My point after all this rambling is fess up. It's not a big deal, we all do it, usually it's just in our heads rather than on our computer or on a piece of paper.
I would just say "Yeah I think your beautiful. Why wouldn't I do that?"
Although you've already lied about it, so stick to that otherwise people will think your full of shit. But if it happens again, don't be embarassed. The truth shall set you free, son.
I wish you the best of luck with how ti plays out.