If something is like watching sausages getting made, unpleasant truths about it emerge that make it much less appealing. The idea is that if people watched sausages getting made, they would probably be less fond of them.
Living together out of wedlock. "They are living over the brush" originates from a form of marriage when a couple held hands and jumped over a besom to signal their commitment to each other, because they couldn't have a church marriage.
(UK) If you look after the pennies, the pounds will look after themselves, meaning that if someone takes care not to waste small amounts of money, they will accumulate capital.
('Look after the pence and the pounds will look after themselves' is an alternative form of this idiom.)
To have loose lips means to have a big mouth, susceptible to talking about everything and everyone. Sinking ships refers to anything from small acquaintances to long and hearty relationships (with friends or a significant other). So when one says loose lips sink ships, one is basically saying if you can't shut up you are going to end hurting people, usually psychologically or emotionally.Loose lips sink ships comes from World War I and/or WWII, when sailors on leave from their ships might talk about what ship they sailed on or where it had come from, or where it was going. If they talked too much (had 'loose lips') they might accidentally provide the enemy with anecdotal information that might later cause their ship to be tracked, and bombed and sunk, hence 'Loose lips sink ships.' Later, it came to mean any excessive talk might sabotage a project.