Shall I Let Sleeping Dogs Lie

We have been together 21 years. We have a child nearly a teenager.
Since we met, we have role-played her taking another cock. She goes along with the explicit dirty talk in the bedroom but never follows through. I've arranged with guys on swinging sites but she's still not been tempted. She won't have people in the house, and rarely goes out or drink. If she drinks which is ultra rare she's a slut but just for me.

She's 5O size 10 fortunate to look much younger. We live in a small village.

We have a new neighbour moved in next-door on his own. Probably 40-45. He is divorced and has his kids weekends.

Nice guy very polite and chatty.

She could easily slip into his house and let him fuck the hot wife she potentially is when our youngster is at school.

Like most men I think I want to see it, but is this too close for comfort.
A guy I volunteer with says his wife brings up having sex with a delivery man every time they have sex. It turns out his wife only mentions the delivery men because he cums very soon after. I do this also every time my wife mentions another cock.
I probably ought to leave well alone and not interfere.