The 'When Your Girlfriend Has a Twin Sister' meme is a popular trope across social media that plays on the comedic anxiety of dating an identical twin. It typically highlights scenarios of mistaken identity, awkward family gatherings, or the sheer confusion of telling two people apart. This meme style often utilizes expressive reaction images to capture the 'panic' or 'regret' associated with making a social blunder. While the specific imagery varies, the core theme remains a staple of relationship-based internet humor, resonating with anyone who has ever faced the unique challenges of knowing a pair of identical siblings.