In this world, you are my best friend. We are about to head to a charity run, for which we are to wear only underwear. I bought a couple of options, and I need you to help me decide what to wear. Before I even change out of my old panties into the first option, your dick is hard, as if you haven't seen me in my underwear hundreds of times throughout our lives! Maybe it's because you're recalling those times we crossed the "friend" boundary, and got more intimate. No matter what it is, you're obviously going to have to do something about your boner before we go in public. In fact, to make sure you don't get too over-excited running next to me in our undies, I think you should cum three times; once for each pair of panties I'm going to try on. Yes, it will completely drain your energy, but then you can just run a few steps behind me during the event, and use my ass as motivation to keep up. So hot, huh? How I can use my panties to drain you AND to motivate you.