“he will find.” That is the reading of the Hebrew text and it takes some thought to properly understand it. The key is thinking about what the man thought he would find when he entered into the adulterous relationship, unwisely listening to the flattery and lies of the adulterous. She promised him lovemaking in sumptuous circumstances and good food, but when it was over what he really “found” was not love (she did not, after all, have any intention of actually being in love with him), but rather affliction and dishonor.
“affliction.” The Hebrew word is nega (#05061 נֶגַע), and it means a blow, thus a wound, and it also can mean a plague or the marks caused by a sickness or plague (HALOT Hebrew-English Lexicon; BDB Hebrew-English Lexicon). If the man is caught committing adultery with another man’s wife, he will almost certainly be beaten up by her family—actually, both he and the woman might be executed, although that punishment was not always enforced.
The Hebrew word’s meaning of “plague” also adds the possibility that the man will get a sexually transmitted disease, although the word “plague” is sometimes used to refer to other afflictions besides actual disease, for example, “That person is plagued by depression,” or “Kansas seems to be plagued by tornados.” Unstated in this verse, but stated elsewhere in Proverbs, is the fact that not only the woman’s family will be angry and vengeful, if the man does not repent, he will face God’s anger on Judgment Day. The way to avoid all the pain that can come from adultery is not to do it.