What is anal sex

Although people tend to associate anal sex with the penetration of the anus by the penis, the term also indicated any other sexual activity that involves the stimulation of the anus.

In anal sex, the stimulation can be either external or penetrative. 

External stimulation involves touching the anal opening orally with the mouth and tongue or manually with the finger. 

Penetrative stimulation involves placing a finger, the penis or a sex toy into the anus.