How to Tell If Someone Is Flirting With You, According to Science Share Photo: fizkes, Shutterstock To sign up for our daily newsletter covering the latest news, hacks and reviews, head HERE. For a running feed of all our stories, follow us on Twitter HERE. Or you can bookmark the Lifehacker Australia homepage to visit whenever you need a fix. Back in the day when we actually used to interact with other people in real life, it wasn’t always clear whether someone was being friendly, wanted something from you, or was actually flirting. After close to a year of strange socially-distant living, we’ve probably not gotten any better at this. If you’re someone who likes to rely on data to navigate your personal relationships, then you may be interested in the findings of a recent study that pinpointed three facial expressions most commonly used when flirting.