It's bs, but I messaged this person just out of sheer curiosity. Here's what I got back:

"Hey there! We're a group of three girls, who are all very close friends. We’re college educated, and are very reserved, intelligent girls. We have never done anything “wild” in our lives, and we are practically the opposite of slutty. The three of us have a male friend, who we are very good friends with, and have been for years and years. He hangs out with us all the time. But just recently, he did something truly awful. Basically, he’s been in a relationship with one of us for most of the time that we’ve known him. But several weeks ago, he ended that relationship, in order to pursue another one of us. As far as we’re concerned, this is unforgivable, and we’ve decided that we’re going to get back at him. How? By making some other guy lucky as all fuck. So we’re looking for a guy who is shy, nerdy, and has never had any luck with girls in his entire life. Specifically, we're looking for a guy who doesn't try to "play it cool", and who isn't afraid to let out his excitement or completely freak out and lose his shit. There's no judgement here, so if you're the kind of guy who is thinking to himself "Oh my god!", or just wants to swear profusely with excitement, or nearly die of happiness, then we're the kind of girls who want to hear it. Ideally, you should be someone who is literally freaking out right now at the very thought of being surrounded by three girls at the same time. Another special thing about our offer, is that it’s open to you even if you’re under 18. We know there are probably a lot of kids who browse reddit, and usually have to pretend to be older. But with us, you don’t have to. We just want you to be brutally honest about yourself, flaws and all, and come find yourself in a situation hotter than you could possibly have imagined. This is not a joke. It is 100% for real. We are exactly who we say we are, and we expect you to be, too."