Is it ok to treat yourself once a week?

Alright first; i work out like a madman and diet to, I've lost 120lbs and now sit at 164lbs and I'm pretty active outside of the gym, i usually treat myself once or twice a week and then hop back on my diet, is this ok to do? I usually find that if i treat myself its easier to stay on my diet p.s and by treat i mean a muffin or something i don't normally eat on my diet, not gorging on food for a day