person A: My wife and I are on a diet together for the last month. We have been doing great but today on my way home from work I stopped for Ice cream and did not tell her.
person B: Hey everyone trips up a little. What you need to remember is that you and your wife made a commitment and you should follow through on that. 
person A: Yea I know. The real issues is that I want to stop again from more tomorrow. 
person B: It's ok to have a cheat day everyone once in a while_comma_ but you can't give in. Be strong!