Happened with a friend’s husband. He butt dialed me and I heard him asking a woman back to a condo they had near one of their restaurants at the beach. I even heard the click click click of her heels in the parking lot as she walked with him to his car. I confronted him and he denied it to my face.
It was more like a purse dial that my wife at the time did.
While I suspected her of being up to something her “calls” confirmed it. When I found hand written directions, not from our home but to our home, my heart sank.
It was one thing to listen in for ten or twenty minutes of chatter and quite another to listen to hours of conversations after I rigged a “voice activated” recorder to our home phone line.
The worst time of my life.