
“Very good question. (pause) I don't think it's a sin but I don't think it should be done.”
in response to the question, "Is adultery a sin."
in the New York Post, February 23, 1990, as archived at the Daily Beast http://www.thedailybeast.com/articles/2016/10/30/donald-trump-in-1990-adultery-is-not-a-sin.html
1990s