Dutch thumb 

When one inserts his/her thumb in their own ass and then asks a friend/co-worker/boyfriend/girlfriend etc. to smell the thumb.

I hate it when John puts his Dutch thumb in my face.

Dutch thumb by V. Price October 24, 2006

dutch thumb 

When a guy is getting ready to cum and the girl sticks her thumb up the guys butt.

I've never had a better orgasm than when Becky gave me a dutch thumb while she was going down on me.

dutch thumb by Tha Chad October 25, 2006

Dutch Thumber 

When you and your friend stick your thumbs up your own asses and then you grab a hold of each others fists and work them up and down. (Similar to a dutch rudder but with thumbs and asses instead of dicks)

Me: "Jem and I gave each other a Dutch Thumber yesterday."

X-Ray: "Is that gay?"

Vav: "Of course its not gay."

Dutch Thumber by The Thumbing Dutchman February 4, 2013