"You should think of it. You don't want to be alone for the rest of your life. You'd die from sexual starvation for a start," Serenena quipped.
"I could bring home a stranger occasionally, to keep the proverbial sexual wolf from the door."
"Or at the door, depending how you look at it," Serena giggled.
Source: Joan O'Neill: "De-Stress". In Irish Girls About Town, 2004, pp. 30–31.
Maybe I am a bit slow on the uptake but I am not able to fully understand the bold passage of the above dialoge. It is not clear to me how it is possible to keep proverbial sexual wolf (probably the reference to the Little Red Riding Hood) from the door when you are admitting that you are planning to have a occasional sex with a stranger. I would understand it when she would say "I could bring home a stranger occasionally to let in the proverbial sexual wolf". Or is it meant that when you will have an occasional sex it will protect you from not to be eaten by sexual wolf (unsatisfied sexual desire).