It is best to avoid eating the mango before sleep. The best time to eat fruits is first thing in the morning after a glass of water. Eating fruits right after a meal is not a great idea, as it may not be digested properly. The nutrients may not be absorbed properly either. You need to leave a gap of at least 30 minutes between a meal and a fruit snack. Ideally, one should eat fruits an hour before the meal or two hours after,

It will not cause any harm. In fact mango is good for digestion. But you should give a gap of minimum 1 and 1/2 hour before slerp