I was like you, wife agreed to try it, I was still not sure how I would feel. But I would get really hard and cum fast talking about it, or even masturbating when I was alone. I would picture her taking BBC's in any position and I knew I wanted to see it. The first time, yes, plenty since, it was just amazing. We found a site and were looking for guys, no rush, one that she was attracted to and had a big cock. We chatted a bit and agreed to meet. When he pulled out his dick and I saw how excited she was, I was hard instantly. I enjoyed every minute of that night as much as her lol. I'm always there when she plays taking pic/video, she never plays alone (for safety reasons).
My suggestion, make sure you talk about your rules/boundaries before anything happens. You both need to be on the same page on what you guys want to do, see, and fee. If you want it, and she wants it, you'll both enjoy.