Self defecation is the act of being able to make fun and/or light of yourself in an effort toward 'humanizing' yourself. Actually that is the definition of 'self deprecation' however self defecation is self deprecation BUT to the 'Nth' degree. To further explain, the antonym of being self deprecative would be 'pompous' while the antonym of being self defecative would be that of a 'complete pompous ass'.
He was trying too hard to fit in by using some self defecation humour and ended up making himself not only the butt of his own jokes, but everyone else's as well. What a complete ass, he sure went overboard.