Back when airlines allowed smoking on-board, I often flew with a co-pilot that smoked, even in the cockpit. When I made Captain, I refused to allow any smoking in the cockpit. If I flew with a F/O (First Officer) that was a smoker, a few of them would go through what almost appeared to be withdraw. I had one F/O that became so nervous and upset that he had to go back in the coach section to have a smoke about once every hour. I guess that a five and a half hour flight is too long to go without a smoke.