Quick answer
An honest, accurate answer is received the way a kiss is. The saying compares straight speech to affection, and it is one line long.
Read both lines
The verse has one line in Hebrew and the whole thing rests on a single image, which is unusual enough to notice. The comparison is startling and was meant to be: a kiss on the lips is intimate, chosen, and unmistakably welcome, and the saying claims that is what a straight answer feels like to the person who gets one.
The word behind "right" means straight or correct, not kind, which keeps the verse from being about pleasant speech. The answer in view might be unwelcome in content. What makes it a kiss is that it is true and that it was actually an answer, given to a person who asked and deserved one. Anyone who has been managed, deflected, or given a careful non-response knows the alternative, and the saying's claim is that being told the truth plainly registers as affection. It sits in this collection between two courtroom sayings, so the answer being described may well be testimony.
Related: Proverbs 15:23 · Proverbs 27:5–6 · Proverbs 16:13 · Proverbs 22:21
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.