Sentence:  “... It's not like I'm just looking for a <WSD>bonk</WSD>, is it? This is something a bit different.” ¶ “Quite,” said Nick—though <WSD>bonk</WSD> was a troublingly casual way of referring to something which preoccupied him so much. 
Meaning of the word marked with <WSD> tags:  An act of sexual intercourse.