Personally, I don't suggest you do it. I'm not sure how bad it was for you to start this diet originally (I found it VERY difficult both times), but having a carb meal, for me, is like quitting smoking and then smoking one after a couple of months - it just sets it all off again. Cheat meals have forced me back into my old style of eating more than once, and I now avoid them at all cost.

However, if you have good self control and don't crave carbs too much, you should be fine.

If it's a matter of indifference and you know the carbs you will be eating will not be INCREDIBLY good, I'd say don't do it