I recently heard a rather novel solution to this age-old predicament. One of my housemates was courting a dashing specimen of a lad (flowing golden locks, underwear-wrecking physique, and so on), and the time came for her to spend some time in his room. Understandably, there was great excitement and speculation while she was away, but we did not anticipate the shocking truth.

She returned several hours later, looking somewhat troubled. Turns out that he had continued his act of entirely failing to notice any of her advances (or maybe he just doesn't like her). But while she was there, she noticed a small glass jar, perhaps five centimetres in diameter, filled with a number of white slivers. On closer inspection, these turned out to be toenail clippings. Thinking that her eyesight must be failing more than usual, she discreetly enquired about the jar.

"Oh, yeah, those are my toenails! Don't worry, I only keep the best ones."