A sex game wherein the bugler alerts his/her friends that they are mid-intercourse by placing their thumb to their lips with a clenched fist and loudly mimicking the sound of a bugle. The friends of the bugler respond to the call by galloping into the room on invisible horses, whilst shouting "charge!" in the style of a 19th century cavalry regiment.
Lad 1 - "That girl sure wasn't impressed with your bugling last night."
Bugler - "Yeh, she cried for ages after the initial shock"