[Edited to add] You know, housekeeping standards aside, I can't imagine how somebody can not notice there's a roach in a cup.

Yeah, no kidding. To me, I can understand "roaches are a constant battle around here; we spray, we clean, and we keep all our food in sealed containers, but we still see 'em from time to time despite our valiant efforts." A roach in a teacup suggests a total indifference to the presence of insects. It's someone who isn't even trying to fight the battle anymore. The occasional roach skittering across the floor when the light is turned on wouldn't make me worry about the health and safety of someone's kids. A roach in my teacup would.