I had something like this happen a few years ago. I wanted to tell a friend of mine about my... interests... and while we were at a friends party/sleepover she mentioned she'd stumbled across some website that mentioned ABs, and how messed up it was that they did that. Funny thing is, about a year or so ago, after she'd apparently become more open-minded, the topic of secrets came up, and I ended up telling her. Her reaction was quite different that time, I assume it was just shock of what it actually was, but she was quite accepting of it.