Family doesn't count. With others, I always pay for gas and other incidentals or try to really hard until it becomes ackward.. When on our boats, its expected but never requested. Just the way we were brought up. Owning, maintaining and running a boat is expensive enough. The "He would have gone anyway" math, just doesn't make any sense to me. LMB guys have it easy, try filling up over 200 gallons and burning most of it in a day or two, not so bad right now, but when it was $4, fueling up was painful.