I am not going ask about the leaving the toilet seat up issue. I share a bathroom with a guy. When he needs it up, he puts it up. When I need it down, I put it down. Simple!
The question club wants to know: For a normal household toilet, rather than a urinal or something... why don't some men flush after urinating? It seems like all the guys I know just leave urine in the toilet for the next person to see/smell.