No problem. Actually I learn that the hard way. I've been reading shoujos and one day I came across a very inocent shounen ai (not even a confession!). Then, thanks to my bad habit of not reading tags or résumés, I started a yaoi without a warning. The first page was a coloured page of a very non censured hot scene. I can tell you I was more than shocked (also that marks my downfall, it wasn't an spiral but a free fall!)
No sex.... T^T *sob sob*