1. an expression implying that knowing to much about an activity, situation or person tends to discourage one from involving himself with it, often related to sexual encounters
see also zipless fuck
2. a truism
3. a parody of loose lips sink ships
After Elliott told Devin that Kittyboot's friend from Philly had roast beef curtains, Devin replied, "Buddy, thanks for warning me... loose lips shrink dicks."
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi