Much like a butt dial, this happens by accident and often the caller is unaware of having done so. The nut dial is typical in two situations:
1. Phone in front pants pocket and catches nut shift.
2. Phone resting on car seat between legs and gets sack dragged.
Dude, I think you butt dialed me yesterday. I finally hung up.
Nah man, I probably nut dialed you. I had my phone on the seat while we were offroading.
Based on the rule that states:
If it looks like a duck, waddles like a duck, and quacks; it's a duck.
Used in real life to explain the obvious truth of the matter.
Dude 1: Andi was sure cranky when I asked her about last night at the bar. She was going with her girlfriends.
Dude 2: Is that all you asked?
Dude 1: Yeh, but when she got home her shirt was inside out, she smelled like cologne and her back is scratched up. I had to ask.
Dude 2: No you didn't. Rule of Duck. Andi is a whore.