1 definition by Matthew Iceton

To chocolate thumb someone is to place your hand in the 'thumb up' position and rest it on a seat next to you so that when a person sits down your thumb goes up their anus.

Penatration of the anus is unlikely when the victim is fully clothed, however not impossible.
F**k off Dave, you've chocolate thumbed me three times tonight!
by Matthew Iceton September 17, 2017
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