Turns out all suspicion is correct. I received a call yesterday night (night she was supposed to come home) she has stayed over at theirs on three occasions now. I got a call from the husband who explained very casually to me that he's piping my wife because she isn't getting satisfaction at home and he said he knows that I have no issue since I don't mind her staying at theirs. I hung up and didn't know what to do, he called back but I didn't answer - he messaged me saying that he knows I'm shocked and don't know how to respond and that he'll phone me, put it aside and let me listen in. I literally felt like cumming from just reading the message, ears ringing and butterflies. I replied with a measly "Ok".
Around 1am (I could not ......) I get a call and answer immediately - I hear my wife getting smashed as if she's a porn star, he made her humiliate me and he made her ...... on his dick, a feat which I've never achieved. I came within 2 minutes of listening. Her wet pussy was easily heard aswell as their kissing. It went from sex to her sucking his dick three times before (I think he came) and hung up, during that 30 mins, it sounded like she came 3 times. But I'm not sure.
I've been thinking about this all day and don't know how to speak to her.
She will be staying until Sunday now ☺️
I've mixed feelings but overall really turned on. Wanked 5/6 times today..