Sometimes, you need to know when to quit and when to walk away. Sometimes, you should also learn to take advice the first time it's given to you… especially when you directly asked for it. This couple would do well to learn this and listen to the advice they received from Reddit's r/AmItheA**hole community this week. The pair made separate posts to the sub to see whether or not the wife was in the wrong for her comments to her husband's sister. Her sister-in-law offered her some advice about th…