You left your phone on the table to go take yourself a drink in the kitchen. Vox passed here and saw your phone left alone on the table. His curiosity took over and he took it. But he had no idea of what your code was, so he tried a random code, 1234, and omg it worked (lmao if it's your code). He was shocked but also amused by a code so simple, and now, your phone was open for him.