The chemicals kill off older sperms (from any previous mating), up-regulates females' egg-laying rate and reduces her desire to re-mate with another male.
The bond of a previous mating can be a strong factor despite a queen's captiousness, but you never know.
The thrusting action which occurs during sexual intercourse manually removes seminal fluid out of the cervix area from a previous mating.
While the male is pregnant, the female starts a new batch of eggs, which are ready at about the same time that the male gives birth to the young from the previous mating.
Many are already paired from previous matings; all are usually nesting, courting, mating and laying within a few days of arrival.