I just had a major milestone birthday, and I decided to really celebrate even if it meant going off program. (I am on WW). I am embarrassed at what I ate because WW is good about teaching you how to plan for big events. I didn't count points, but I did stop eating when I was full.
My DH and I booked a weekend at a resort on the ocean. DH had the pastry chef there bake me a special birthday cake and I spent the weekend enjoying all foods that I loved. (DH and I are both on WW and he knew that I wanted cake this year. He wasn't trying to sabotage me.)
On the following Monday morning, I went right back on program. When I weighed in last Friday, I had gained less than a pound!
The NSV for me was getting right back on program and then getting back on the scale. In the past, when I would go off program, I would just feel like a failure and quit completely. I really am trying to break old habits.