The idea came to me several years ago. I was reading stories online of men who talk their wives into having sexual encounters with other men. The idea first didn't set well with me. Picturing my wife spread open on another man's cock, sucking a stranger's dick into her warm mouth, or rubbing her pussy on a man's face. I felt jealous inside thinking of these things, and my stomach turned at the idea. Gradually though, after reading more stories and watching more cheating wife and cuckold videos, I started to warm up to the idea.
My wife, Kelly, and I have always had a semi-open relationship, even after marriage. Kelly is bisexual, and I have been supportive of that. I allowed her to have girlfriends, and on occasion there was sharing or a threesome. These weren't things I demanded, but never turned them down when the opportunity presented itself. After she had sex with her girlfriends, she would be so worked up she would want my cock as soon as she got home. Things like this didn't make our relationship, but they added to the excitement.
Several months ago I have begun to fantasize about my wife sucking another man off. I told Kelly on a couple occasions that if she brought a man home from the bar, I'd watch her suck his dick. I told her it would be hot, getting to see what I experience from a different point of view. She would tell me she didn't know if she could do that, and the conversation would die there.