When a male is recieving oral sex, and immediately prior to ejaculation, he pulls his member out of her mouth and procedes to make a downwards chopping motion with it on her forehead. As he ejaculates it will give the illusion that small woodchips are flying out from the 'ax'
Bill: Hey brosef, how was your night with Tracy?
Bob: Epic, I put on my flannel shirt and pulled the lumberjack.
Bill: Nice work.