After you came back home, at this very ordinary afternoon, everything seems normal excluding your lovely girlfriend who looks really nervous today. Something is obviously going on as she just can not look directly in your eyes and is avoiding any form of contact with you. What could possibly happen?
... Did you miss your anniversary of forgot about her birthday? Nah, everything looks just fine, so what could it be... Some time later she just can not stand this awkward silence anymore and has something she wants to talk with you about.