The Lie About My Lunch Break

I promised my wife I'd take a lunch break today to run errands at home. But instead, I spent an hour playing video games and eating ice cream in bed, she’ll be pissed if she finds out. Is it okay to keep this small lie? It was just once, right? Oh wait, last week, I also told her my bike got a flat tire, but I took the car anyway... Am I being too petty here or is this something more serious?