I liked the advice I read somewhere online:

"You can cheat whenever you want...you just have to eat it naked, in front of a mirror."

Works for me!
However, I have been:

on a road trip...three green apple martinis
dinner at my Dad's...my stepmom's world class lasagna
brother's birthday...B&J's Pistachio Pistachio ice cream

However, each time there was at least three weeks since any cheats...I got right back on the wagon...and I didn't do it again for at least three or four more weeks.
I think the biggest danger is not being able to stop.
As long as I keep my portions small and don't indulge for more than one meal, I am still losing. Or getting smaller, which is the main thing. Also, I am very fussy. I don't Indulge for just anything! It has to be what I consider fantastic stuff.