when a dude is thinking of another dude while sticking his thumb up his ass.

To stick a thumb in the anus while jerking off.

When you're lying next to your partner (preferably when they are sleeping but awake works just as well) adjust your hand into the hitchhiker position (thumb up) and launch your thumb directly into their butthole. After insertion is complete, make sure to thank them for the ride ;)

When your wife,girlfriend or significant other bends, over you sneak behind them. While they are bent over,go between their legs and using your hitchhiker thumb start from the crotch to the rear saying " Need a ride".

1. When someone sticks their thumb up their own ass or someone else's ass.
2. To sit on one's thumb

The act of sticking ones thumb into the anal area of another person or perpetrator.

A Reality Porn Site. Where Men In A Limo Pick Up Teen Hitchikers. And Talk Them Into Having Sex With Them