No proof? Are you sure? Not a single telling physical or digital thing?
What about intimate physical attributes?
There's almost always proof I would think.
My xAP's husband told my BW. He's never confronted me. If he did I'd both apologize and thank him. My wife and he met a few times to compare notes and he gave her correspondence. They decided on high road for both family's kids sakes - i.e. he didn't confront me. It's been silence for 18 months until he sent my BW a note recently saying he was getting a divorce, and wondering how she was doing. Sad.