Love is Blind Season 11

"Love Is Blind" star John Shannon is coming clean about what ultimately destroyed his marriage to Sarah Williams ... admitting he crossed the line with a stripper who also worked as an escort.

During Sunday's Season 11 reunion, John finally gave more details about the incident that led to the couple's split, revealing it happened during a boys' night out about six months earlier.

John insisted nothing physical happened, but acknowledged he crossed a boundary Sarah had established in their marriage. He also admitted he later exchanged inappropriate text messages with the woman he met that night.