I have an anus. You have an anus. We all have an anus!!!
n. pl. a·nus·es
The opening at the lower end of the alimentary canal through which solid waste is eliminated from the body. Also called anal orifice, fundament.
Anuses are not only for the disposal of solid waste even if that sounds like enough fun for one night. Your anus plays an important role for your abilities to enjoy safe and healthy sex.
Some people have said that they like having something in their anus during sex, with no pressure or movement, just presence. Other folks are really turned on by objects -- a finger, penis, or dildo -- moving in a rhythmic motion in their anus (they like the sensations deep inside). Whatever you like, have fun and be safe.
In case you didn't click that fine link I'd like to say that it contained information from Columbia University and since universities are never wrong you better believe that you would like an object -- a finger, penis, or dildo -- moving in a rhythmic motion in your anus.