.. that was the answer to one of my comments on the relationship advice subreddit.

Does anyone else feel like people are going insane? What kind of gibberish nonsense is that only to paraphrase cheating and degenerate behaviour? The fact that this was upvoted while my comment was heavily attacked speaks volumes.

Edit: Notice how he never mentions any "cheating". It's just "If you know she is sleeping with someone else you can open the relationship or leave her."