I'm not as sober as my kids think
why do you lie to them
I don't want to ruin the impression I am making on my kids. They'll be disappointed in me.
I understand that you don't want to disappoint your kids but you should be honest about yourself. They're going to find out eventually.
Why not enjoy getting drunk a bit longer?
Being dishonest with your kids about your sobriety will teach them to be dishonest also. You are creating problems for your kids that they will have to live with for the rest of their lives. Be responsible and honest with them.