mechanic hands 

Hands with precise finger movements due to years of doing handy work, such as fixing cars

The guy I was with last night had mechanic hands, I couldn't stop squirting.

mechanic hands by Robots225 September 20, 2019

mechanic hand 

Ramming your fingers into a girl's rectum, causing your fingers to look as if you are a mechanic.

I just got so much shit under my finger nails, I look like I have a mechanic hand.

mechanic hand by Thommy94 December 14, 2006