Don't make up stories. Telling lies is dumb, it just takes one little inconsistency and things start to unravel. Best to just make punting something which fits into the normal routine of work/play, whatever. There are a number of useful points here about cell phones, I would add one more: just ignore the occasional call from your wife/partner; train her to expect that you are a bit unreliable but never explain why. Message her to say you might be late but nothing more. Precision and too much information is not a good idea, and never ever arrive home with a guilt present, flowers or chocolates - you will have to explain why?