Is it normal to constantly check out my sister's body?

There is nothing wrong with looking at a sexy girl - and nothing wrong with flirting with her - an nothing wrong with seducing her - and nothing wrong with sharing a romantic moment with her - and nothing wrong with making love to her... ESPECIALLY IF SHE IS YOUR SISTER!

My brothers always check me out. I have flirted with them since I was very young, AND we've seen each other naked several times. Although, It would take a lot of sexual tension combined with our horniness for us to have sex. IF the opportunity presented itself (with those conditions), OH, Hell yeah... I'd sex them hard. They are my brothers, and I love them very much. I'm sure it would be the most amazingly intense sex of our lives.

As you can tell... I have a fantasy of it happening, but it just hasn't happened yet. We live a great distance from each other now, but given the right circumstances, I'd do it. YOU ARE NORMAL... it is normal to have those thoughts, and more common than you may think to have incest with siblings.

So, if the timing is right, and the feeling is mutual, then just go for it. Ease into it - no rush, since it is a delicate relationship with siblings, but don't deny yourself of a special relationship you could have with your sister... definitely put it on the "to do" list.

(Wow, that comment was longer than I thought it would be)

Well historically it's normal. And as long as it doesn't become dating it's fine.

I'd think it would kind of be hard not to, if you're straight. I don't know though.

As long as you aren't thinking about trying to have sex with her.

Kill yourself.