Buggery with a difference:
Normally done whilst buggering a young
lady (typically one who rides side-saddle).
The young lady ingests a piece of ham or
bacon tied to a fine thread, which the man holds whilst buggering her.
As the man is nearing ejaculation he pulls the thread, along with the attached piece of
meat, which causes the
woman to heave (convulse).
A side effect of the heaving is for the sphincter to contract violently around the man's penis, thus hightening sensations and giving a more powerful ejaculation.