You two had been a couple for three years now... She is very affectionate, talks the whole time, wants your attention at all times and always wants to be glued to you, however... After an outing with friends where you made some joke, one of her friends laughed a lot...

From that moment, you noticed she started to go quiet and you already knew what was coming... When you got home, she just dropped onto the sofa and turned on the TV

You asked her... Sitting on the sofa where she just ignored you, watching TV, she only gave you a flat look once

Clearly she won't tell you openly... But she's definitely upset