what kind of plug? can you illustrate it by a picture? 

  Jeng Geng Dee la....
EC come liao.... I mean plug then plug liao.

alright. you win. 

This is because a male cat's penis has a band of about 120–150 backwards-pointing penile spines, which are about one millimeter long;[156] upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. This act also occurs to clear the vagina of other sperm in the context of a second (or more) mating, thus giving the later males a larger chance of conception

i pun entah la..