Is it normal to piss in tinnies instead of walking 5m to the toilet

sometimes I drink out of cans at home. After a while however I start to need a piss; instead of trecking 5m to he toilet I tend to just piss in the empty tinnies I've drank from (is this normal A.) the odd thing I find is that I practically overflow the tinnie with my piss every time, in short is it normal to piss the exact amount out as you drunk if not a little bit more???