Replying to Nutting vs sacking a rail

I was talking to my skater friend about skiing and I used the term “nutting a rail”. This confused the shit out of my friend and I proceeded to get clowned on.

This brings me to the question, why do skiers say nut when skaters say sack? I’ve heard skiers use both words but saying “i nutted on a rail” instead of “I got sacked on a rail” seems to only exist within skiing.

I get that nuts and sack are pretty interchangeable words for balls but who’s idea was it to make it sound like we ejaculate on rails??