ofcourse one should lend money when ur best buddy needs that and if without your help it is next to impossible to get rid of the situation. But one should also consider that the money lend is to get "rid" of the situation and if the situation is genuinly made by your friends such as stupid decision or anything and not a natural disaster(like some disease) then one can regret in lending the money because if one lends money in this manner then he is indirectly supporting his friends stupid decision. Thus one can take decision depending on his instinct. Also one can decide to lend a part of money asked, which is not burdensome to you.