Green’s Dictionary of Slang

bumps-a-daisy n.

(N.Z. sexual intercourse) .

[NZ]R.H. Morrieson Predicament 182: ‘That’s old Vern Bramwell’s wife.’ ‘So what,’ said Mervyn. ‘All the better. He gives her the dough-ray-me and the boys give her bumps-a-daisy’ [Simes:DLSS].