there is no specific term in the field of psychology or psychiatry for the compulsion to slip a finger into a yawning person's mouth. This behavior may be considered inappropriate or intrusive and can vary in motivation and intent depending on the individual.
Compulsions are typically associated with Obsessive-Compulsive Disorder (OCD) and are repetitive behaviors performed to reduce distress or prevent a feared outcome related to an obsession. The behavior you mentioned does not fit the typical pattern of OCD compulsions.
If someone experiences urges or behaviors that they find difficult to control or that cause distress to themselves or others, it is essential to seek guidance from a qualified mental health professional. They can help assess the situation, provide an accurate diagnosis if necessary, and offer appropriate treatment options. It's important to remember that addressing such behaviors with professional help can lead to a better understanding and management of the underlying issues.