This is SO embarrassing, but I cant talk to anyone else about it. And I honestly don't know what to do.

My roommate I had at my apartment had to break her lease we had due to a family emergency. She was willing to find someone to sublet her room and pay her half of the bills, but then I would be in an apartment with someone I did not know. I felt bad for her, and I wanted to help her out somehow. That's when my parents suggested letting my younger brother move in with me. They pretty much came right out and said they were sick of him living at home, and since he had a steady job, it was time for him to move out.
My brother Paul is 4 years younger than me - he dropped out of college, but was able to get a job working on the ramp at the airport. He actually makes pretty good money, so I knew financially I could trust him. He and I have always been pretty close, too, so I decided to let him move in with me at the beginning of this month.

We had a lot of fun this past weekend - we went out bar hopping and it was more like we were friends than we were brother and sister. I had broken up with a guy I was very serious with about a month ago, my brother was "in between" girlfriends as he put it - so it was nice to have each other for company.

Two nights ago - I went to bed before he did, and a few hours later I heard the t.v on pretty loud. Since my bedroom wall and where the t.v is in the living room are back-to-back, I went out to ask him to turn it down. Paul was sound asleep on the couch and snoring away - so I went to turn off the t.v completely.
That's when I noticed he just had a pair of boxer shorts on - and his penis was kind of hanging out of them. My first instinct was to turn away and just go back to my room, but I ended up staring at it. Even though just the head of his cock was poking out, I could tell he had some pretty good girth there. I always thought of Paul as my little brother - but as I looked as his cock, I realized he was a "man".
I got horny!
I could not believe that I had to go back to my room and take care of myself for awhile, just because I saw my brothers penis.

Now its all I can think about....

I find myself wearing as little as possible when he is around now, hoping he might think of me sexually like I have been thinking about him.

I want to see more of his cock - I want to see it big and hard, but how would I ever tell him that?
I wish I could just come right out and say "I saw your cock the other day...."....omg.
I sometimes wonder what if HE is having the same kinds of thoughts about me?

How I wish I could just come right out and say something, and if it does not work out - go back in time and take it all back.

I know its so wrong and so sick - but I cant help but think how much fun we could be having with each other.

How can I let him know?