When you wake up with a raging hard-on caused by having a full bladder. You have to stand way back from the toilet and lean way forward so that your pee will go into the bowl, rather than going all over the wall. In this position, you will resemble one of those downhill skiiers doing a ski jump.
Sheila: What the heck are you doing? You look like you're doing a ski jump in the bathroom.
David: I had to pee, and if I don't stand like this, my hard-on will shoot pee all over the potted plant you put on top of the toilet. Don't I look like a downhill skiier pee-er?
Sheila: That thing sure is big.