Is it okay to cheat?
On your diet, it is definitely okay to cheat. According to Dr. John Berardi founder of Precision Nutrition, you only have to be strict about 90% of the time. The other 10% is basically free to do whatever.
I really like this concept, but don't fall into the idea that you can do whatever. Even though you are cheating by eating this or drinking this, or not exercising on a typical exercise day, you should still be smart about it. If you are not going to exercise on a typical day remember that you should eat less than you normally do. If you are going to cheat your diet, than tell yourself, "If I want to eat it, than I need to deserve it." Go exercise either a little harder or a little longer than usual before you eat it. That way you can at least even your calories burned to calories consumed. Whatever your choice is, you can still lose weight by only being strict to your diet and exercise 90% of the time.
Before you think it is okay to cheat on your diet, you must know how much you're actually burning during an exercise program. If you are only maintaining your weight during your normal exercise days and have a decent diet or even gaining weight back on these days that you cheat, you may not be burning enough calories during and after exercise. This means you need to probably work harder and/or longer. Just by telling yourself, "Wow that was a hard workout", doesn't necessarily mean it was a hard workout. A hard workout is when you burn more than the average amount of calories. More sweat than last time doesn't mean it was a harder workout either. Lets save this for another time. Until then find an exercise specialist to test you to see how many calories you're burning during your workouts.