A human who exists for the purpose of providing male mammels with a life into which it can watch its semen pour. Key elements of a cum dumpster are that it must feel degraded and disgusted with itself even though it orgasms while its user spurts hot seed into it. All females and many males are cum dumpsters.
I wish I could stop openning my mouth and allowing my wife to watch me serve as a cum dumpster, taking the hot stream of sperm which poured out of her cunt after she had been used as a cum dumpster by her brother and his friends. I was a cum dumpster's cum dumpster, and I hated myself for enjoying the used loads I ate.