If you have a car that has power seatbelts,do you use the lap belt with it?

I love having the motorized belts in my car, its nice not having to actually put the belt on. My friend and I went to the store yesterday in her car that has the same kind of belts but she wouldnt drive until I put my lap belt on too, Ive never seen anyone so about it. just wondering if im the only one that never puts theirs on. thanks!