British slang
Yet another coined term meaning the contents of the testicles.
However "plaster of penis" is usually too wordy to actually thread into a sentence and so is never often used as a metaphor for come/cum.
"Fredrick the novelist was having enormous trouble including 'Plaster of Penis' into his pornographic literature, as it spoiled the rhythm of his sentence structure."
"Father MacDougall made a tissue sculpture using plaster of penis as his glue."
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.