Pee all over the toilet seat.
This happened all the time with my FIL, I would have to wipe and clean the seat after he went home.
I have had a male friend round my house a few times for coffee this month, and he also leaves urine on the toilet seat.
I know I'm generalising, but I find this so weird and, judging by the state unisex loos are often left in, I wonder if some men are just prone to shake it everywhere? 
Is this common 