Being degraded gets you off more than anything else.
Show me slut. Roll onto your back and spread your bound arms and legs as wide as you can, but don't let those pens that are stuffing your ass fall out of your hole. Stay in that humiliating pose and think about what others will think of your as you degrade yourself. Imagine how you must look with your asshole stretched so widely and you being bound like a total whore.
Look at me as you revel in your humiliation.