Definitions by MarkHanna
Thumbkin
Performing the act of splinting on a consensual female partner, while performing oral sex on her. This involves inserting your thumb into her vagina, pushing down towards the anus to help her relieve constipation, while sucking on her clit.
Thumbkin
Performing the act of splinting on a consensual female partner, while performing oral sex on her. This involves inserting your thumb into her vagina, pushing down towards the anus to help her relieve constipation, while sucking on her clit.