Intimidate him/her or use shaming language if you can't think of a witty reply like those above. It may cost you a bang, but since cockblock is already underway you've got nothing to lose. I like to say: "Yeah, I've got a basement and I like to use it to punish random girls I meet. How did you guess?".
Check out my thread Essential android tools for modern players and alphas to find out how to make your android phone your wingman, or click here and scroll down if you only need to root it.
Want sound that puts iPods and iPhones to shame? I got you covered!