FWIW, In reality, the proof I had wasn't really "concrete" and from what I have read and heard many guys will still deny deny deny even in the face of such proof (mine was an email string between the two of them). Many guys will even deny if you have pictures of them kissing OW, hugging OW etc. I've heard many horror stories. From what I've read and heard most guys will deny for as long as possible so expect it.

FW came clean pretty easily I thought.

BFM

There is only one person who could ever make you happy, and that person is you.
David Burns, Intimate Connections