Caught on tv, in the NCIS episode “Dead and Unburied” (#4.5) (2006). The team is examining a murder scene, studying the carpet intently:
Dr. Donald ‘Ducky’ Mallard [the medical examiner]: Looks like sisal. It’s a naturally stiff fiber woven from the leaf of the cactus plant. It doesn’t matt, trap dust, build static, makes it ideal for carpeting. Personally, I prefer a good shag. [Gibbs and McGee just look at him while Palmer grins like a loon]
Ducky uses the noun shag referring to a type of rug, but everyone else hears the nominalization of the verb shag ‘fuck’. Merriment ensues.