Rule 1 — Attitude Towards Sexual Freedom
From G.R. Taylor's Rules of Matrism/Patrism Explained

Patrist Restrictive
To meet the demands of duty Patrists must have a restricted attitude to all bodily functions. To be good citizens all biological impulses must be controlled. Every urge, from breaking wind to copulation, must be held in check until it may safely be released, as dictated by manners, decency and honour. Inevitably sexual urges must be restrained.

Matrist Permissive
Whereas the Matrist disdain for duty is disdain for any restraint, so the only limits Matrists place upon their sexual desire are those dictated by convenience.