廝熟

familiar with one another

mutually / with one another / manservant / boy servant / guy (derog.)

(bound form) together; each other / (bound form) male servant / (bound form) dude; so-and-so (used in 那廝|那厮[na4 si1] and 這廝|这厮[zhe4 si1])

ripe; mature / thoroughly cooked; done / familiar; acquainted / experienced; skilled / (of sleep etc) deep; profound / also pr. [shou2]