a sexual practice peculiar to Australians whereby the male mounts his wife doggy-style, holds firmly to her tits then tells her that her sister has a much tighter cunt. The male must then hold on for dear life as wife furiously tries to buck him off. Said to be one of the most exhilarating forms of sexual intercourse possible.
Jack: How come you're walking funny?
Bob: The missus gave me a tasmania bullride last night and I think she's buggered my back.