Frotage
The act of rubbing ones genitals on inanimate objects to induce ejaculation and/or acheive pleasureable sensations.
On the way home last night, I had a spot of frotage on the neighbours wall.
frotaging
When you touch people up on the train.
Keithy just frotaged me on the train, he did it so hard i'm sore, frotaging is so cool