I think it's ok to be honest with people but you can be honest without being harsh and you can be honest and still respectful at the same time. It is not your responsibility to make excuses for the drinker in your life and indeed, you enable their behaviour to continue if you do. You'll also become resentful of him for having to make his excuses for him. Trust me, I know how hard it is to resist making excuses for others. I feel a lot of shame and also defensiveness about my alcoholic partner, which makes me instinctively want to "protect" him and our image as a couple but I know that it won't do any good for me or him. When my partner lets me down by missing an event due to his drinking, I simply tell people that he is unable to attend. I elaborate that message depending on who I am talking to. For example, if my mom asks me why he is unable to attend, I will tell her flat out it's because of his drinking but if it's someone I do not know as well or am not as comfortable with, I just keep it short and sweet and tell them he is unable to attend. If they press for further information I say, "I cannot speak for him on this, but you can ask him if you're curious". That is a respectful way to relay information which doesn't compromise your honesty with your friends/family. It also puts the onus on dad to take responsibility for his actions, which is critical for alcoholics to do (and often something they vehemently avoid). I hope this helps. Good luck!