30 [M4A] Fantasising about my wife cuckolding me

I've been with my wife since we were teenagers, never been with another girl and she's never been with another guy. I kind of feel bad for her that she's only ever slept with me, and now I can't stop thinking about my wife fucking another guy. It's getting me so horny. The prospect of her being railed by a big guy while I watch is too much for me.

It's gotten to the point now whenever we're having sex, I spend the whole time imaging someone else is fucking her and I'm watching. Needless to say I barely last a minute before I cum when I start thinking about that.

I don't know when this started but now it's all I think about, I've proposed to her the idea of her sleeping with other people a few times. At first she didn't seem into it, then out of the blue she proposed us having an open relationship. This excited me, but tbh I'm happy just her sleeping around! All I want is her to come home after being used and satisfied.

Would love to chat to anyone who's into this, in this lifestyle, has any advice or just wants a horny chat.