The Messenger of Allah (sal Allahu alaihi wa sallam) said: “Save yourself from nudity because two angels are with you all the time, except when you go to the toilet or engage in sexual intercourse: So, be bashful of them and respect their presence.” [Tirmidhi]
Allah (subhana wa ta’ala) has pronounced clothes to be a blessing in the Quran and has clearly stated that they serve the purpose of beautifying, protecting and covering those parts of the human body which a person instinctively considers wrong to expose. Nudity is looked down upon and desiring to expose oneself arises out of a perversion of human nature.
Even when we think that we are alone we should not unnecessarily take our clothes off because there are always at least two angels with us. In honour of them we should maintain a dignified state.