Verb: to accidentally dial someone with your cellphone by putting pressure on your phone during sex, causing the listener to hear the sounds of you having sex with someone. Happens when you leave your phone on the bed, or it falls out of your pocket and on to the backseat of a car, onto the couch, etc.
Fuckdialing example: "Me and this girl were banging on her couch and her knee ended up on top of her cellphone--she totally fuckdialed her mom. After we finished we suddenly heard this tiny voice saying 'Hello? Hello?' She was mortified."
Making unintended phone calls while fucking. Generally caused when someone leaves a cell phone on the bed, causing random buttons to be pressed during sex.
Similar to ass dial
After fuck dialing girlfriends other boyfriend last night at 2am, he got a little pissed.