Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Mistress
Mistresses, like friends, are lost by letting ’em handle your money.
—Sir John Vanbrugh
Mistresses are like books. If you pore upon them too much, they doze you, and make you unfit for company; but if used discreetly you are the fitter for conversation by ’em.
—William Wycherley